Electronics & Communication Quiz - 1
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What is Cathode Ray?
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Alpha-Ray
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Beta-ray
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Gamma-ray
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None
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About This Quiz
This is a very elementary Quiz containing questions from Solid State Devices, Basic Electronics, etc
Quiz Preview
- 2.
Who discovered Electron?
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Thomas Alva Edison
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Michael Faraday
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Alexander G. Bell
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J. J. Thomson
Correct Answer
A. J. J. ThomsonExplanation
J. J. Thomson is credited with the discovery of the electron. In 1897, he conducted experiments using cathode rays and discovered that they were composed of negatively charged particles, which he called electrons. This discovery revolutionized the understanding of atomic structure and laid the foundation for the development of modern physics. Thomas Alva Edison, Michael Faraday, and Alexander G. Bell made significant contributions in their respective fields, but they were not the ones who discovered the electron.Rate this question:
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- 3.
What is the polarity of Anode
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Negative
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Positive
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Neutral
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Not applicable
Correct Answer
A. PositiveExplanation
The anode is the positively charged electrode in an electrical circuit. It attracts negatively charged particles, such as electrons, and facilitates the flow of current. Therefore, the correct answer is positive.Rate this question:
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- 4.
What is the polarity of Cathode
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Negative
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Positive
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Neutral
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Not applicable
Correct Answer
A. NegativeExplanation
The polarity of the cathode is negative because in an electrical circuit, the cathode is the electrode where electrons flow out of. Electrons are negatively charged particles, so when they flow out of the cathode, it gives the cathode a negative polarity.Rate this question:
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- 5.
What is 1 Torr of pressure
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76cm of Hg
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1cm of Hg
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1mm of Hg
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1 micron of Hg
Correct Answer
A. 1mm of HgExplanation
1 Torr of pressure is equivalent to 1mm of Hg. Torr is a unit of pressure named after the Italian physicist Evangelista Torricelli, who invented the mercury barometer. It is defined as the pressure exerted by a column of mercury 1mm high at 0 degrees Celsius under standard gravity. Therefore, 1 Torr is equal to 1mm of Hg.Rate this question:
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- 6.
What is the Pressure in a Vacuum-Tube?
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76cm of Hg
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1cm of Hg
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1mm of Hg
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1 micron of Hg
Correct Answer
A. 1 micron of HgExplanation
The pressure in a vacuum-tube is commonly measured in millimeters of mercury (mm Hg) or in some cases in microns of mercury (μm Hg). The given answer of "1 micron of Hg" indicates that the pressure in the vacuum-tube is extremely low, as 1 micron is equal to 0.001 mm. This suggests that the vacuum-tube has a pressure close to absolute zero, making it an ideal vacuum with almost no gas particles present.Rate this question:
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- 7.
What is the charge of electron?
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1.6*10^-19
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=-1.6*10^-19
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0
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None
Correct Answer
A. =-1.6*10^-19Explanation
The charge of an electron is -1.6*10^-19. This value represents the fundamental unit of negative charge carried by an electron. The negative sign indicates that the electron has a negative charge, while the magnitude of the charge is given by 1.6*10^-19.Rate this question:
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- 8.
What is the spin of electron?
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0(h/2pi)
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(1/2)(h/2pi)
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H/(2pi)
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None
Correct Answer
A. (1/2)(h/2pi)Explanation
The spin of an electron is a quantum mechanical property that describes its intrinsic angular momentum. It is quantized and can only take on certain values. In this case, the correct answer is (1/2)(h/2pi), which represents half of Planck's constant divided by 2π. This value is commonly used to denote the spin of an electron.Rate this question:
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- 9.
What Statistics is followed by electron?
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Bose-Einstein
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Fermi-Dirac
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Gaussian
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None
Correct Answer
A. Fermi-DiracExplanation
Fermi-Dirac statistics is followed by electrons. This statistical distribution describes the behavior of particles with half-integer spin, such as electrons, under the laws of quantum mechanics. It determines the probability of finding electrons in different energy states within a system, taking into account the Pauli exclusion principle, which states that no two electrons can occupy the same quantum state simultaneously. This statistical model is essential in understanding the behavior of electrons in various physical systems, such as metals and semiconductors.Rate this question:
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- 10.
What are the no. Of elements in a Diode?
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1
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2
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3
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4
Correct Answer
A. 3Explanation
A diode is a two-terminal electronic component that allows current to flow in only one direction. It consists of three elements: an anode, a cathode, and a PN junction. The PN junction is formed by joining a P-type semiconductor and an N-type semiconductor. Therefore, the correct answer is 3, as there are three elements in a diode.Rate this question:
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- 11.
What is the function of filament in a VT?
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No function
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To cause thermionic emission
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To cause photo-ionic emission
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To cause high field emission
Correct Answer
A. To cause thermionic emissionExplanation
The function of the filament in a VT (vacuum tube) is to cause thermionic emission. Thermionic emission is the process by which electrons are emitted from a heated filament, creating a flow of current in the vacuum tube. The filament acts as a source of heat, causing the electrons to gain enough energy to overcome the work function and escape from the surface of the filament. This emission of electrons is essential for the operation of the vacuum tube.Rate this question:
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- 12.
What is the function of Cathode in VT?
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No function
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To emit electrons
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To capture electrons
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To suppress electrons
Correct Answer
A. To emit electronsExplanation
The function of the cathode in a vacuum tube (VT) is to emit electrons. The cathode is a heated element that releases electrons through a process called thermionic emission. These emitted electrons then flow towards the anode, creating an electric current within the vacuum tube.Rate this question:
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- 13.
What is the function of Anode in VT?
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No function
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To emit electrons
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To capture electrons
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To suppress electrons
Correct Answer
A. To capture electronsExplanation
The function of the anode in a vacuum tube (VT) is to capture electrons. When a voltage is applied to the anode, it attracts the negatively charged electrons emitted by the cathode. This flow of electrons from the cathode to the anode forms the current in the vacuum tube. The anode is designed to have a positive charge to attract and collect the electrons, allowing for the desired operation of the VT.Rate this question:
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- 14.
What is the number of electrodes in Pentode
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5
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4
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3
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2
Correct Answer
A. 5Explanation
A pentode is a type of vacuum tube that has five electrodes. These electrodes are the cathode, control grid, screen grid, suppressor grid, and plate. Each electrode plays a specific role in the amplification and control of the electron flow within the tube. Therefore, the correct answer is 5.Rate this question:
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- 15.
What is the number of electrodes in TRIODE
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2
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3
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4
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5
Correct Answer
A. 3Explanation
The number of electrodes in a TRIODE is 3. A TRIODE is a type of vacuum tube that consists of three electrodes: a cathode, a control grid, and a plate. The cathode emits electrons, the control grid controls the flow of electrons, and the plate collects the electrons. These three electrodes work together to amplify or control electrical signals.Rate this question:
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- 16.
What is the number of electrodes in TETRODE
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2
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3
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4
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5
Correct Answer
A. 4Explanation
A tetrode is a type of vacuum tube that has four electrodes: a cathode, a control grid, a screen grid, and a plate. These electrodes are used to control the flow of electrons and amplify signals in electronic circuits. Therefore, the correct answer is 4.Rate this question:
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- 17.
What is the unit of resistance?
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Ohms
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Henry
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Farad
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Radians
Correct Answer
A. OhmsExplanation
The unit of resistance is Ohms. Ohms is the standard unit of electrical resistance in the International System of Units (SI). It is named after the German physicist Georg Simon Ohm, who formulated Ohm's law. Resistance is the measure of how much a material or device opposes the flow of electric current. It is represented by the symbol Ω. Henry is the unit of inductance, Farad is the unit of capacitance, and Radians is the unit of angular measurement.Rate this question:
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- 18.
What is the unit of current?
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Coulombs
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Coul/sec=Ampere
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Volt
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Ohms
Correct Answer
A. Coul/sec=AmpereExplanation
The unit of current is Ampere, which is represented as Coul/sec. This means that current is measured as the amount of charge (Coulombs) passing through a point in a circuit per unit time (seconds). Ampere is the standard unit for measuring electric current in the International System of Units (SI).Rate this question:
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- 19.
What is the unit of capacitance ?
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Ohms
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Henry
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Farad
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Radians
Correct Answer
A. FaradExplanation
The unit of capacitance is the farad. Capacitance is a measure of an object's ability to store electrical charge. The farad is a unit of measurement for capacitance and is defined as one coulomb of charge per volt of potential difference. It is named after the English physicist Michael Faraday.Rate this question:
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- 20.
What is the unit of Inductor ?
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Ohms
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Henry
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Farad
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Radians
Correct Answer
A. HenryExplanation
The unit of an inductor is Henry. Henry is the SI unit of inductance, named after Joseph Henry, an American scientist. Inductance is a property of an electrical circuit that opposes changes in current flow. It is measured in Henry and represents the ratio of the induced electromotive force to the rate of change of current. Ohms is the unit of electrical resistance, Farad is the unit of capacitance, and Radians is the unit of angular measurement.Rate this question:
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- 21.
What is the unit of energy ?
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Watt
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Joules
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V/m
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C/m^2
Correct Answer
A. JoulesExplanation
Joules is the correct answer because it is the standard unit of energy in the International System of Units (SI). Energy is defined as the capacity to do work or produce heat, and joules measure the amount of energy transferred or converted. Watts, V/m, and C/m^2 are not units of energy, but rather units of power, electric field intensity, and electric charge density, respectively.Rate this question:
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- 22.
What is 1 eV of energy?
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1Joules
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0.1Joules
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0.001Joules
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1.6*10^-19Joules
Correct Answer
A. 1.6*10^-19JoulesExplanation
1 eV of energy is equal to 1.6*10^-19 Joules. The electron volt (eV) is a unit of energy commonly used in physics and chemistry to describe the energy of subatomic particles. It is defined as the amount of energy gained or lost by an electron when it moves through an electric potential difference of one volt. The conversion factor between eV and Joules is 1 eV = 1.6*10^-19 Joules. Therefore, the correct answer is 1.6*10^-19 Joules.Rate this question:
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- 23.
When 1 Coulomb of Charge falls through 1V
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0.1J gained
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1J gained
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10J gained
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100J gained
Correct Answer
A. 1J gainedExplanation
When 1 Coulomb of charge falls through 1V, 1J of energy is gained. This is because the energy gained or lost by a charge can be calculated using the formula E = qV, where E is the energy, q is the charge, and V is the voltage. In this case, the charge is 1 Coulomb and the voltage is 1V, so the energy gained is 1J.Rate this question:
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- 24.
1V into 1 Amp is equal to
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1 Joule
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1 Joule/s=1W
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10W
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100W
Correct Answer
A. 1 Joule/s=1WExplanation
The unit of power is watt (W), which is defined as the rate at which work is done or energy is transferred. One joule per second (J/s) is equal to one watt (W). Therefore, 1V (volt) into 1 Amp (ampere) is equal to 1 watt (W).Rate this question:
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- 25.
1Coulomb is subjected to 1V/m electric field
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10 N Force developed
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1 N force developed
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(1/10)N developed
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100N developed
Correct Answer
A. 1 N force developedExplanation
The given information states that 1 Coulomb is subjected to a 1V/m electric field. According to Coulomb's law, the force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. Since the electric field strength is given as 1V/m, we can infer that the force developed is 1 Newton (N).Rate this question:
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- 26.
Q coulomb charge creates D(R) electric flux density
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Q/(R^2)
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Q/(4πR^2)
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Q/(8πR^2)
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Q/(16πR^2)
Correct Answer
A. Q/(4πR^2)Explanation
The electric flux density created by a coulomb charge is inversely proportional to the square of the distance from the charge. This is represented by the formula Q/(4πR^2), where Q is the charge and R is the distance. As the distance increases, the electric flux density decreases. The factor of 4π in the denominator is derived from the formula for the surface area of a sphere, which represents the spreading out of the flux over the surface area. Therefore, the correct answer is Q/(4πR^2).Rate this question:
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- 27.
D electric flux density is equal to
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εE
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µH
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µε
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None
Correct Answer
A. εEExplanation
The correct answer is εE because electric flux density (D) is defined as the amount of electric flux passing through a given area per unit area. It is directly proportional to the electric field (E) and the proportionality constant is ε, which represents the permittivity of the medium. Therefore, D = εE.Rate this question:
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- 28.
B magnetic flux density is equal to
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εE
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µH
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µε
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None
Correct Answer
A. µHExplanation
The correct answer is µH. This is because magnetic flux density (B) is equal to the product of the permeability of the medium (µ) and the magnetic field strength (H). Therefore, B = µH.Rate this question:
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- 29.
Velocity of Light 'c' in free space is equal to
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1/√(µε)
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1/√(µoε0)
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√(µoε0)
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None
Correct Answer
A. 1/√(µoε0)Explanation
The correct answer is 1/√(µoε0). This is because the velocity of light in free space is determined by the properties of the medium it is traveling through. In this case, the medium is free space, which has a specific combination of permeability (µo) and permittivity (ε0). The equation 1/√(µoε0) represents the relationship between these two properties and the velocity of light in free space.Rate this question:
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- 30.
µo is
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Absolute permittivity
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Absolute permeability
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Absolute reluctance
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None
Correct Answer
A. Absolute permeabilityExplanation
The correct answer is "absolute permeability." This refers to the measure of a material's ability to allow the flow of magnetic flux. It is a property of the material and is denoted by the symbol µo. It is a fundamental constant in electromagnetism and is used in calculations involving magnetic fields and induction. Absolute permeability is different for different materials and is often measured in henries per meter (H/m).Rate this question:
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- 31.
εo is
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Absolute permittivity
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Absolute permeability
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Absolute reluctance
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None
Correct Answer
A. Absolute permittivityExplanation
The correct answer is "absolute permittivity." Absolute permittivity, denoted by εo, is a fundamental constant in physics that represents the ability of a material to store electrical energy in an electric field. It is a property of the medium in which the electric field exists and is related to the capacitance of a capacitor. It is used in calculations involving electric fields, such as in Gauss's law and the calculation of capacitance.Rate this question:
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- 32.
Relative permittivity of air is
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4
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3
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2
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1
Correct Answer
A. 1Explanation
The relative permittivity of air is 1. Relative permittivity, also known as dielectric constant, is a measure of how well a material can store electrical energy in an electric field. Air has a relative permittivity of 1 because it is a non-polar substance with no permanent electric dipole moment. This means that air does not have the ability to store electrical energy efficiently compared to other materials.Rate this question:
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- 33.
Relative permeability of air is
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1
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2
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3
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4
Correct Answer
A. 1Explanation
The relative permeability of air is 1 because air is considered to be a non-magnetic material. Relative permeability is a measure of how easily a material can be magnetized in the presence of a magnetic field compared to a vacuum. Since air does not possess magnetic properties, it cannot be easily magnetized and therefore has a relative permeability of 1.Rate this question:
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- 34.
Value of µo is
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1H/m
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2H/m
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4π×10^-7 H/m
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5H/m
Correct Answer
A. 4π×10^-7 H/mExplanation
The value of µo, also known as the permeability of free space, is 4π×10^-7 H/m. This value represents the ability of a material to allow magnetic fields to pass through it. It is a fundamental constant in physics and is used in various calculations involving electromagnetism.Rate this question:
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- 35.
Potential Drop
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Integral of E
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First derivative of E
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Second derivative of E
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None
Correct Answer
A. Integral of EExplanation
The correct answer is "Integral of E" because the potential drop across a circuit element is equal to the integral of the electric field (E) along the path of the circuit element. This integral represents the work done per unit charge to move the charge through the circuit element, resulting in a change in potential. Therefore, the integral of E is directly related to the potential drop.Rate this question:
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- 36.
Electric Field is
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Positive potential grad
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Negative potential grad.
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Second derivative of potential
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None
Correct Answer
A. Negative potential grad.Explanation
The correct answer is "negative potential grad." This is because the electric field is defined as the negative gradient of the electric potential. The electric potential describes the amount of electric potential energy per unit charge at a given point in space. The negative sign in front of the gradient indicates that the electric field points in the direction of decreasing potential. Therefore, the electric field is in the opposite direction of the potential gradient and is considered negative.Rate this question:
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- 37.
Newton×Meter
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Joule
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Watt
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Derivative of Watt
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None
Correct Answer
A. JouleExplanation
The correct answer is Joule. Joule is a unit of energy in the International System of Units (SI), equal to the work done by a one newton force acting over a one meter distance. It is commonly used to measure energy and work. In this context, Newton×Meter is another way of expressing Joule, as it represents a force of one newton applied over a distance of one meter. Therefore, the answer is Joule.Rate this question:
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- 38.
Kg×m/s^2
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Joule
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Newton
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Watt
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None
Correct Answer
A. NewtonExplanation
The given correct answer is "Newton". Newton is the unit of force in the International System of Units (SI). It is defined as the amount of force required to accelerate a mass of one kilogram by one meter per second squared. Therefore, Newton is the appropriate unit for measuring force, which is represented by the equation F = m × a, where F is force, m is mass, and a is acceleration.Rate this question:
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- 39.
Mgh
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Kinetic energy
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Potential energy
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Thermal energy
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None
Correct Answer
A. Potential energyExplanation
The given answer, potential energy, is correct because "mgh" represents the formula for gravitational potential energy. "m" refers to the mass of an object, "g" represents the acceleration due to gravity, and "h" indicates the height of the object. When an object is lifted against gravity, work is done on it and it gains potential energy. Therefore, potential energy is the most appropriate choice among the given options.Rate this question:
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- 40.
(1/2)mv^2
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Kinetic energy
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Potential energy
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Thermal energy
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None
Correct Answer
A. Kinetic energyExplanation
The equation (1/2)mv^2 represents the formula for kinetic energy, which is the energy possessed by an object due to its motion. The variables m and v represent the mass and velocity of the object, respectively. Therefore, the correct answer is kinetic energy.Rate this question:
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- 41.
I (moment of inertia)×ω(radians/sec)
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Energy
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P(linear momentum)
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J(angular momentum)
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None
Correct Answer
A. J(angular momentum)Explanation
The equation I * ω represents the rotational kinetic energy of an object, where I is the moment of inertia and ω is the angular velocity in radians per second. The equation p represents linear momentum, which is the product of an object's mass and its linear velocity. The equation J represents angular momentum, which is the product of an object's moment of inertia and its angular velocity. Therefore, the correct answer is J, as it represents angular momentum.Rate this question:
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- 42.
(1/2)I×ω^2
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Linear kinetic energy
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Rotational Kinetic Energy
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Potential energy
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None
Correct Answer
A. Rotational Kinetic EnergyExplanation
The given expression, I×ω^2, represents the rotational kinetic energy. The variable I represents the moment of inertia, which is a measure of an object's resistance to rotational motion. The variable ω represents the angular velocity, which is the rate at which an object rotates. When these two values are multiplied and squared, it gives us the rotational kinetic energy, which is the energy associated with the object's rotational motion.Rate this question:
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- 43.
Torque×angle
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Watt
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Angular acceleration
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Rotational energy
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None
Correct Answer
A. Rotational energyExplanation
Rotational energy refers to the energy possessed by an object due to its rotation. It is dependent on both torque and angle. Torque is the force that causes an object to rotate, while angle represents the distance through which the object rotates. The product of torque and angle determines the amount of rotational energy. Therefore, rotational energy is the correct answer as it encompasses both torque and angle in the context of rotational motion.Rate this question:
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- 44.
Moment of Inertia×Angular Acceleration=
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Linear force
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Torque=Rotational Force
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Angular velocity
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None
Correct Answer
A. Torque=Rotational ForceExplanation
The equation Moment of Inertia × Angular Acceleration = Torque represents the relationship between the moment of inertia, angular acceleration, and torque in rotational motion. Torque is the rotational force that causes an object to rotate around an axis, and it is directly proportional to the product of the moment of inertia and angular acceleration. Therefore, the given answer correctly identifies that torque is equal to rotational force in this equation.Rate this question:
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- 45.
Current × Resistance
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Electric Field
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Magnetic Field
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Voltage drop
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None
Correct Answer
A. Voltage dropExplanation
Voltage drop refers to the decrease in electric potential across a component or circuit due to the resistance encountered by the current flowing through it. It is a result of Ohm's law, which states that the voltage drop across a resistor is directly proportional to the current flowing through it and the resistance of the resistor. Therefore, when current flows through a resistor, a voltage drop occurs across it.Rate this question:
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- 46.
What is the material in Cathode?
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Tungsten
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Copper
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Strontium Barium CuO
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Aluminum
Correct Answer
A. Strontium Barium CuOExplanation
The material in the cathode is Strontium Barium CuO. The cathode is the electrode in an electrical device where reduction occurs. Strontium Barium CuO is a compound made up of strontium, barium, copper, and oxygen. It is commonly used as a cathode material in certain types of batteries and fuel cells due to its high conductivity and stability.Rate this question:
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- 47.
What is the Work Function of StBaCuO?
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0.5eV
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1eV
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2eV
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3eV
Correct Answer
A. 1eVExplanation
The work function of a material is the amount of energy required to remove an electron from the material's surface. In this case, the work function of StBaCuO is 1eV, meaning that it takes 1 electron volt of energy to remove an electron from the surface of StBaCuO.Rate this question:
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- 48.
At what temperature Thermionic Emission occurs
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500◦C
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1000◦C
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2000◦C
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3000◦C
Correct Answer
A. 1000◦CExplanation
Thermionic emission is the process where electrons are emitted from a heated surface. It occurs when the temperature of the surface is high enough to provide sufficient energy for the electrons to overcome the potential barrier and escape. In this case, the correct answer is 1000◦C, indicating that at this temperature, the surface is sufficiently heated to allow for thermionic emission to occur.Rate this question:
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- 49.
What atomic model did Thomson propose?
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Solar-System Model
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Plum-Pudding Model
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Bohr's Model
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None
Correct Answer
A. Plum-Pudding ModelExplanation
Thomson proposed the Plum-Pudding Model of the atom. This model suggests that the atom is composed of a positively charged "pudding" with negatively charged electrons embedded within it, resembling plums in a pudding. This model was proposed in 1904 and was later disproven by the experiments of Rutherford, leading to the development of the nuclear model of the atom.Rate this question:
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