Online Quiz - By Ecea
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Make your brain work on a perfect blend of electronics and general knowledge
Questions and Answers
- 1.
A(n) ________ is the smallest component of every element.
Explanation
An atom is the smallest component of every element. Atoms are composed of protons, neutrons, and electrons. They are the building blocks of matter and cannot be broken down into smaller particles while still retaining their chemical properties. Atoms combine to form molecules and compounds, which make up all substances in the universe. Therefore, the correct answer is atom.Rate this question:
- 2.
The relation of the voltage across an inductor to its current is described as
- A.
A. leading the current by 90 degrees
- B.
B. lagging the current by 90 degrees
- C.
C. leading the current by 180 degrees
- D.
D. in phase with the current
Correct Answer
A. A. leading the current by 90 degreesExplanation
When the voltage across an inductor is plotted against the current flowing through it, the voltage waveform will be ahead of the current waveform by 90 degrees. This means that the voltage reaches its peak value before the current does. This phase relationship is characteristic of an inductor, where the voltage leads the current.Rate this question:
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- 3.
Materials with permeabilities slightly less than that of free space are referred to as
- A.
A. Diamagnetic
- B.
B. Ferromagnetic
- C.
C. Non-magnetic
- D.
D. Paramagnetic
Correct Answer
A. A. DiamagneticExplanation
Diamagnetic materials have permeabilities slightly less than that of free space. Diamagnetism is a property of materials that causes them to create a weak magnetic field in opposition to an externally applied magnetic field. This weak magnetic field is created by the orbital motion of electrons in the material. As a result, diamagnetic materials are repelled by magnets and have a negative magnetic susceptibility.Rate this question:
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- 4.
Inserting a soft iron core into a coil has what effect on the inductance of the coil?
- A.
A. Increase inductance
- B.
B. Decrease inductance
- C.
C. Does not affect the inductance
- D.
D. None of these
Correct Answer
A. A. Increase inductanceExplanation
Inserting a soft iron core into a coil increases the inductance of the coil. This is because the soft iron core enhances the magnetic field produced by the coil, resulting in a stronger magnetic field and increased inductance.Rate this question:
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- 5.
The natural magnet refers to
- A.
A. Steel
- B.
B. Soft iron c. Magnesia b. Soft iron c. Magnesia b. Soft iron
- C.
C. Magnesia
- D.
D. Lodestone
Correct Answer
D. D. LodestoneExplanation
Lodestone is the correct answer because it is a type of rock that naturally possesses magnetic properties. It is a form of magnetite, which is a mineral made up of iron oxide. Lodestone has been used for centuries as a natural magnet, attracting other magnetic materials. It is believed that lodestone was one of the first materials used by ancient civilizations to create compasses and navigate the seas.Rate this question:
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- 6.
A battery with a rating of 9 volts has an internal resistance of 20 ohms, what is the expected resistance of the bulb that is connected across the battery to attain a maximum power transfer?
- A.
A. 20 ohms
- B.
B. 10 ohms
- C.
C. 5 ohms
- D.
D. 2 ohms
Correct Answer
A. A. 20 ohmsExplanation
The expected resistance of the bulb that is connected across the battery to attain maximum power transfer is equal to the internal resistance of the battery. This is because maximum power transfer occurs when the load resistance is equal to the internal resistance of the source. In this case, the internal resistance of the battery is given as 20 ohms, so the expected resistance of the bulb should also be 20 ohms.Rate this question:
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- 7.
The reciprocal of capacitance is called________(
- A.
A. Elastance
- B.
B. Permitivitty
- C.
C. Permeability
- D.
D. Conductance
Correct Answer
A. A. ElastanceExplanation
The reciprocal of capacitance is called elastance. Elastance is a measure of how much a material resists being deformed when subjected to an applied force. In the context of capacitance, elastance refers to the ability of a capacitor to store and release electrical energy. It is the inverse of capacitance, meaning that as capacitance increases, elastance decreases, and vice versa. Elastance is measured in units of inverse farads (F⁻¹).Rate this question:
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- 8.
Which of the following cannot be included in a loop of Kirchhoff’s Voltage law
- A.
A. Current sources
- B.
B. Voltage sources
- C.
C. Resistance
- D.
D. Reactance
Correct Answer
A. A. Current sourcesExplanation
Kirchhoff's Voltage Law states that the sum of the voltage drops in a closed loop in a circuit is equal to the sum of the voltage sources in that loop. This means that all the voltage sources in a loop must be included in the application of Kirchhoff's Voltage Law. However, current sources do not have a voltage drop associated with them, as their current is constant regardless of the voltage across them. Therefore, current sources cannot be included in a loop of Kirchhoff's Voltage Law.Rate this question:
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- 9.
Find the phase angle between the voltage across through the circuit when XC is 25 ohms, R is 100 ohms and XL is 50 ohms.
- A.
A. 76 degrees with voltage leading the current
- B.
B. 14 degrees with the voltage lagging the current
- C.
C. 14 degrees with the voltage leading the current
- D.
D. 76 degrees with the voltage lagging the current
Correct Answer
C. C. 14 degrees with the voltage leading the currentExplanation
When XC is greater than XL, the circuit is capacitive. In a capacitive circuit, the voltage leads the current by a phase angle. Therefore, the correct answer is c. 14 degrees with the voltage leading the current.Rate this question:
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- 10.
The all-pass filter is sometimes called a _____
- A.
A. Tow Tomas filter
- B.
B. Delay equalizer
- C.
C. KHN filter
- D.
D. State-variable filter
Correct Answer
B. B. Delay equalizerExplanation
The all-pass filter is sometimes called a "delay equalizer" because it is designed to introduce a delay in the signal without affecting its magnitude or frequency response. This delay can be used to align the phase response of the signal, making it useful in applications such as audio processing or telecommunications where phase coherence is important. The term "delay equalizer" accurately describes the function and purpose of the all-pass filter.Rate this question:
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- 11.
A series connected circuit consists of 3 loads and consume a total power of 50 Watts. It was reconfigured such that 2 are in parallel and the other load is in series with the combination. What is the expected power to be consumed then?
- A.
A. 50 Watts
- B.
B. 25 Watts
- C.
C 75 watts
- D.
D. 45 watts
Correct Answer
A. A. 50 WattsExplanation
When the circuit is reconfigured such that 2 loads are in parallel and the other load is in series with the combination, the total power consumed remains the same. Therefore, the expected power to be consumed is still 50 Watts.Rate this question:
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- 12.
Highest operating frequency can be expected in case of
- A.
A. bipolar transistor
- B.
B. JFET
- C.
C. MOSFET
- D.
D. IGFET
Correct Answer
B. B. JFETExplanation
JFET (Junction Field Effect Transistor) can be expected to have the highest operating frequency compared to the other options. This is because JFETs have a simpler structure and fewer capacitances compared to bipolar transistors and MOSFETs. The simplified structure of JFETs allows for faster switching speeds and higher frequency performance. Additionally, JFETs have a lower input capacitance, which reduces the time required for charging and discharging, enabling them to operate at higher frequencies. Therefore, JFETs are known for their high-frequency capabilities.Rate this question:
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- 13.
If the gain of an amplifier without feedback is 10 and with negative feedback is 8, then the feedback fraction is
- A.
A. 0.025
- B.
B. 0.9
- C.
C. 0.8
- D.
D. 0.225
Correct Answer
A. A. 0.025Explanation
The feedback fraction can be calculated using the formula: Feedback Fraction = (Gain without feedback - Gain with feedback) / Gain without feedback. In this case, the gain without feedback is 10 and the gain with negative feedback is 8. Plugging these values into the formula, we get (10 - 8) / 10 = 2 / 10 = 0.2. Therefore, the feedback fraction is 0.2, which is equivalent to 0.025.Rate this question:
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- 14.
______is used for counting of binary information.
- A.
A. clamper circuit
- B.
B. Schmitt trigger
- C.
C. bistable vibrator
- D.
D. monostable vibrator
Correct Answer
C. C. bistable vibratorExplanation
A bistable vibrator is a type of electronic circuit that is used for counting binary information. It has two stable states, which can be represented as 0 and 1, allowing it to count the presence or absence of binary signals. This makes it suitable for counting binary information in various applications.Rate this question:
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- 15.
. A 33-kohm resistor is connected in series with a parallel combination made up of 56-kohm resistor and a 7.8-kohm resistor. What is the total combined resistance of the three resistors?
- A.
A. 39067 ohms
- B.
B. 49069 ohms
- C.
C. 63769 ohms
- D.
D. 95000 ohms
Correct Answer
A. A. 39067 ohmsExplanation
The total combined resistance of resistors in series is equal to the sum of their individual resistances. In this case, the 33-kohm resistor is in series with the parallel combination of a 56-kohm resistor and a 7.8-kohm resistor. The total resistance of the parallel combination can be calculated using the formula: 1/Total Resistance = 1/56k + 1/7.8k. Solving this equation gives the total resistance of the parallel combination as approximately 6.97k. Adding this to the 33-kohm resistor gives a total combined resistance of approximately 39.067k or 39,067 ohms.Rate this question:
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- 16.
The kind of oscillator found in an electronic wristwatch is the
- A.
A. Armstrong
- B.
B. Clapp
- C.
C. Colpitts
- D.
D. Quartz crystal
Correct Answer
D. D. Quartz crystalExplanation
The correct answer is d. Quartz crystal. Quartz crystals are commonly used as the oscillator in electronic wristwatches. Quartz has a property called piezoelectricity, which means it can generate an electric charge when mechanical stress is applied to it. This property is utilized in the quartz crystal oscillator, where the crystal is cut and shaped in a way that it vibrates at a specific frequency when an electric current is applied to it. These vibrations are used to keep time in the wristwatch.Rate this question:
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- 17.
A 220-volt, 60Hz is driving a series RL circuit. Determine the current if R = 100 ohms and 20 mH inductance
- A.
A. 2.2A(lagging)
- B.
B. 2.0 A(lagging)
- C.
C. 2.2 A(leading)
- D.
D. 2.0 A(leading)
Correct Answer
A. A. 2.2A(lagging)Explanation
In a series RL circuit, the current lags behind the voltage due to the presence of inductance. The given circuit has a resistance of 100 ohms and an inductance of 20 mH. The current can be determined using Ohm's law and the formula for the impedance of an RL circuit. The impedance (Z) is given by the square root of the sum of the resistance squared (R^2) and the inductive reactance squared (Xl^2). The inductive reactance (Xl) is calculated by multiplying the inductance (L) by the angular frequency (ω), which is 2π times the frequency (f). In this case, the frequency is 60 Hz, so the angular frequency is 2π * 60 = 120π. Therefore, Xl = (20 * 10^-3) * (120π) = 24π ohms. The impedance is then calculated as Z = sqrt((100^2) + (24π^2)). The current (I) can be found by dividing the voltage (V) by the impedance (I = V / Z). Since the voltage is 220 volts, the current is 220 / Z. Evaluating this expression gives a value of approximately 2.2 A. Since the current lags behind the voltage in an RL circuit, the answer is 2.2 A(lagging).Rate this question:
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- 18.
Capactors are a type of battery?
- A.
Yes it can be used as a Battery
- B.
No it only holds a small charge
- C.
It is nothing like a Battery
Correct Answer
B. No it only holds a small chargeExplanation
Capacitors are not a type of battery. While both capacitors and batteries can store and release electrical energy, they function in different ways. Batteries use chemical reactions to generate and store electrical energy, while capacitors store electrical energy in an electric field. Capacitors can hold a small charge for a short period of time, but they cannot provide a continuous and sustained flow of electricity like a battery can. Therefore, the statement "No, it only holds a small charge" accurately describes the role of capacitors.Rate this question:
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- 19.
What is the standard operating level of professional audio equipment?
- A.
+10 dBV
- B.
+4 dBu
- C.
-10 dBV
- D.
-20 dBSPL
Correct Answer
B. +4 dBuExplanation
The standard operating level of professional audio equipment is +4 dBu. This level is commonly used in professional audio systems and represents a balanced line level signal. It is a reference to the voltage level of the audio signal, indicating a nominal level of 1.23 volts. This level ensures that the audio signal is at an optimal level for processing and amplification without introducing excessive noise or distortion.Rate this question:
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- 20.
Convert 1110101 binary to octal.
- A.
125
- B.
79
- C.
165
Correct Answer
C. 165 -
- 21.
Convert 451 decimal to octal.
- A.
443
- B.
703
- C.
112
Correct Answer
B. 703Explanation
To convert a decimal number to octal, we divide the decimal number by 8 repeatedly until the quotient is 0. The remainders obtained in each division will be the octal digits in reverse order. In this case, when we divide 451 by 8, we get a quotient of 56 and a remainder of 3. When we divide 56 by 8, we get a quotient of 7 and a remainder of 0. Finally, when we divide 7 by 8, we get a quotient of 0 and a remainder of 7. Therefore, the octal representation of 451 is 703.Rate this question:
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- 22.
What is the legendary Argentianen Football player Maradona's last name
- A.
Wayne
- B.
Diego
- C.
Carlos
- D.
Pablo
- E.
Chicken
Correct Answer
B. DiegoExplanation
The correct answer is Diego because Diego Maradona is a legendary Argentinean football player and "Maradona" is his last name.Rate this question:
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- 23.
Which of the following is not a UNO Agency?
- A.
International Labour Organization
- B.
International Monetary Fund
- C.
Food and Agricultural Organization
- D.
International Postal Union
Correct Answer
D. International Postal UnionExplanation
The International Postal Union is not a UNO Agency. The International Labour Organization, International Monetary Fund, and Food and Agricultural Organization are all UNO Agencies. The International Postal Union is a specialized agency of the United Nations, but it is not considered a UNO Agency.Rate this question:
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- 24.
The size of screwdriver is determined by the shank
- A.
Length.
- B.
Weight.
- C.
Temper.
- D.
Width.
Correct Answer
A. Length.Explanation
The size of a screwdriver is determined by the shank length. The shank refers to the cylindrical portion of the screwdriver that fits into the handle. The length of the shank determines the reach and accessibility of the screwdriver in different applications. A longer shank allows for reaching screws in deeper or hard-to-reach areas, while a shorter shank is suitable for more compact spaces. Therefore, the length of the shank is a crucial factor in determining the size and functionality of a screwdriver.Rate this question:
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- 25.
Which Latin name of a constellation is not paired with an English version?
- A.
Aries - ram
- B.
Cancer - crab
- C.
Draco - dragon
- D.
Sagittarius - swan
Correct Answer
D. Sagittarius - swanExplanation
The Latin name for Sagittarius is not paired with an English version of "swan." The correct English version for Sagittarius is "archer" or "the archer."Rate this question:
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- 26.
Whose cities organised the Kumbh Mela.?
- A.
Allahabad
- B.
Naagpur
- C.
Naasik
- D.
Banaras
Correct Answer(s)
A. Allahabad
C. NaasikExplanation
The Kumbh Mela is organized by the cities of Allahabad and Nasik. Allahabad is one of the main cities where the Kumbh Mela takes place, and it is considered one of the holiest cities in Hinduism. Nasik is another city that organizes the Kumbh Mela, and it is also considered a sacred place. Both cities have a long history and tradition of hosting this religious gathering, attracting millions of pilgrims from all over the world.Rate this question:
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- 27.
The effect of noise depends on the
- A.
Deflection, frequency, and volume.
- B.
Frequency, volume, and duration of exposure.
- C.
Deflection, volume, and duration of exposure.
- D.
Deflection, frequency, and duration of exposure.
Correct Answer
B. Frequency, volume, and duration of exposure.Explanation
The effect of noise depends on the frequency, volume, and duration of exposure. Frequency refers to the pitch of the noise, with higher frequencies being more damaging to the ears. Volume refers to the intensity of the noise, with louder sounds causing more harm. Duration of exposure refers to the length of time a person is exposed to the noise, with longer exposure times increasing the risk of hearing damage. All three factors - frequency, volume, and duration of exposure - play a role in determining the impact of noise on an individual.Rate this question:
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- 28.
The size of screwdriver is determined by the shank
- A.
Length.
- B.
Weight.
- C.
Temper.
- D.
Width.
Correct Answer
A. Length.Explanation
The size of a screwdriver is determined by the shank length. The shank length refers to the portion of the screwdriver that extends from the handle to the tip. It is an important factor in determining the suitability of the screwdriver for different tasks. A longer shank allows for better reach and access to screws in tight spaces, while a shorter shank is more suitable for smaller screws or precision work. Therefore, the length of the shank is a key factor in determining the size of a screwdriver.Rate this question:
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- 29.
Lincoln’s main aim during the war was:
- A.
To free the slaves
- B.
To preserve the Union
- C.
To prevent slavery from expanding into the West
- D.
None of the above
Correct Answer
B. To preserve the UnionExplanation
During the war, Lincoln's main aim was to preserve the Union. While he did eventually issue the Emancipation Proclamation to free the slaves, this was a strategic move to weaken the Confederacy rather than his primary goal. Lincoln believed that preserving the Union was essential for the future of the United States and he prioritized this objective throughout the war. His focus on maintaining the unity of the nation guided his decisions and actions during this tumultuous period.Rate this question:
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- 30.
Which black leader made this statement to President Lincoln: “This is our country as much as it’s yours, and we will not leave it.”
- A.
Martin Delany
- B.
James Forten
- C.
Fredrick Douglass
- D.
None of the above
Correct Answer
C. Fredrick DouglassExplanation
Frederick Douglass made this statement to President Lincoln. This statement reflects Douglass' belief that African Americans have just as much right to the United States as anyone else and should not be forced to leave. Douglass was a prominent black leader and abolitionist who fought for the rights and freedom of African Americans during the Civil War era. He believed in the importance of equality and justice for all, and this statement exemplifies his commitment to those principles.Rate this question:
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- 31.
Approximately what percentage of sailors in the Union Navy were black
- A.
25%
- B.
20%
- C.
15%
- D.
10%
Correct Answer
D. 10%Explanation
Approximately 10% of sailors in the Union Navy were black. This suggests that a relatively small proportion of the sailors in the Union Navy were of African American descent. This could be due to various factors such as racial discrimination, limited opportunities for black individuals to join the Navy, or other social and historical factors that may have influenced the composition of the Navy during that time period.Rate this question:
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- 32.
What does each stand of of DNA Replication contain?
- A.
One strand
- B.
Two parent strands
- C.
Two new strands
- D.
One parent strand & one new strand
Correct Answer
D. One parent strand & one new strandExplanation
During DNA replication, each strand of DNA serves as a template for the synthesis of a new complementary strand. This means that one of the strands is the original parent strand, while the other strand is the newly synthesized strand. Therefore, each DNA replication contains one parent strand and one new strand.Rate this question:
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- 33.
What parts of the flower belong to the carpel?
- A.
Style
- B.
Sepal
- C.
Petals
- D.
Stigma
- E.
Ovary-Ovule
- F.
Petals
- G.
Anther
- H.
Filament
Correct Answer(s)
A. Style
D. Stigma
E. Ovary-OvuleExplanation
The carpel is the female reproductive organ of a flower, and it consists of three main parts: the stigma, style, and ovary. The stigma is the sticky structure at the top of the carpel that receives pollen during pollination. The style is the long, slender tube that connects the stigma to the ovary. The ovary contains the ovules, which are the structures that eventually develop into seeds after fertilization. Therefore, in this question, the parts of the flower that belong to the carpel are the style, stigma, and ovary-ovule.Rate this question:
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- 34.
Bureaucracy is a division of government best described as...
- A.
Composed of elected officials (Ex: Prime Minister, the Cabinet)
- B.
As one that makes decisions, implements policies, administers government’s resources.
- C.
The branch of government that makes laws.
- D.
The branch made up of councilors, advisors, etc working for government leaders
- E.
All of the above.
Correct Answer
D. The branch made up of councilors, advisors, etc working for government leadersExplanation
The correct answer is "the branch made up of councilors, advisors, etc working for government leaders." This answer accurately describes bureaucracy as a division of government that consists of individuals such as councilors and advisors who work for government leaders. Bureaucracy is responsible for assisting in decision-making, policy implementation, and the administration of government resources. It is not composed of elected officials or the branch that makes laws, although it may work closely with these branches.Rate this question:
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- 35.
This law was created in 1215 in England and stated that no one was above the law. It is...
- A.
Habeas Corpus
- B.
Magna Carta
- C.
Rule of Law Act
- D.
British North America Act
- E.
None of the above.
Correct Answer
B. Magna CartaExplanation
The Magna Carta, created in 1215 in England, is a historical document that established the principle that no one, including the king, is above the law. It served as a foundation for the rule of law and the protection of individual rights. The Magna Carta limited the power of the monarchy and introduced the concept of due process, ensuring that individuals could not be imprisoned or deprived of their property without a fair trial. It is considered a significant milestone in the development of democratic principles and the protection of civil liberties.Rate this question:
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- 36.
Who was the Father of Conservatism?
- A.
Thomas Hobbes
- B.
John Locke
- C.
Jean Jacques Rousseau
- D.
Niccolo Machiavelli
- E.
St. Thomas Aquinas
Correct Answer
A. Thomas HobbesExplanation
Thomas Hobbes is considered the Father of Conservatism because of his influential work in political philosophy. He believed that humans are inherently selfish and that a strong central government is necessary to maintain order and prevent chaos. Hobbes argued for the preservation of traditional institutions and the importance of social stability. His ideas laid the foundation for conservative political thought, emphasizing the need for authority and the limitations of individual freedoms.Rate this question:
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- 37.
Astronomy was used to:
- A.
Predict the onset and the end of monsoon season
- B.
Schedule the beginning and end of various yajnas
- C.
Both a and b are correct
- D.
All of the above are false
Correct Answer
C. Both a and b are correctExplanation
Astronomy was used to predict the onset and the end of the monsoon season because ancient civilizations observed celestial events such as the movement of stars and planets to determine the changing seasons. Additionally, astronomy was also used to schedule the beginning and end of various yajnas, which were religious rituals performed during specific celestial alignments. Therefore, both options a and b are correct.Rate this question:
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- 38.
What is the Story behind Holi?
- A.
Ram defeating Ravan
- B.
Prahlad and his unbreakable faith
- C.
The victory of the Pandavas over the Kauravas
- D.
Independence of India
Correct Answer
B. Prahlad and his unbreakable faithExplanation
The story behind Holi is associated with Prahlad and his unbreakable faith. According to Hindu mythology, Prahlad was a young prince who was a devotee of Lord Vishnu. Despite his father's attempts to kill him, Prahlad's faith in Lord Vishnu remained unshaken. His aunt, Holika, who had a boon to be immune to fire, tried to burn Prahlad but ended up getting burnt herself while Prahlad survived due to his unwavering faith. This incident symbolizes the victory of good over evil and the burning of Holika is celebrated as Holika Dahan or Choti Holi, which is followed by the colorful festival of Holi.Rate this question:
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- 39.
A ball is thrown horizontally at a speed of 20m/s from the top of a cliff. If the horizontal speed of the ball is decreased, the time required for the ball to fall 30m will
- A.
Decrease
- B.
Increase
- C.
Remain the same
Correct Answer
C. Remain the sameExplanation
When a ball is thrown horizontally from the top of a cliff, the only force acting on it is gravity. The horizontal speed of the ball does not affect the vertical motion, meaning that the time required for the ball to fall 30m will remain the same regardless of the horizontal speed. This is because the vertical motion is solely determined by the force of gravity and the vertical distance traveled, while the horizontal motion is independent of the vertical motion. Therefore, changing the horizontal speed will not affect the time it takes for the ball to fall 30m.Rate this question:
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- 40.
A is moving towards B, B is moving towards C & C is moving towards A. All are moving with same speed "u".Initial side of the triangle is "2a". Time after which they will meet each other is
- A.
2a/u
- B.
4a/3u
- C.
4a/√3u
- D.
2a/√3u
Correct Answer
C. 4a/√3uExplanation
Concider any two particles, relative separation between them is 2a and relative velocity between them is 3u/2.
so time after which they will meet is rel. sep./ rel. vel.Rate this question:
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- 41.
A motorcycle patrolman starts from rest at A two seconds after a car, speeding at the constant rate of 120 km/h, passes point A. If the patrolman accelerates at a rate of 6m/s^2 until he reaches his maximum permissible speed of 150 km/h, which he maintains, calculate the distance "s" from point A to the point at which he overtakes the car.
Correct Answer
912 m
912 metersExplanation
The motorcycle patrolman starts accelerating 2 seconds after the car passes point A. During these 2 seconds, the car has traveled a distance of 120 km/h * (2/60) h = 4 km/h. The patrolman then accelerates at a rate of 6 m/s^2 until he reaches his maximum speed of 150 km/h. The time it takes for the patrolman to reach his maximum speed can be calculated using the equation v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time. Rearranging the equation to solve for t, we get t = (v - u) / a. Plugging in the values, we get t = (150 km/h - 0 km/h) / (6 m/s^2) = 25 seconds. During this time, the patrolman has traveled a distance of 0.5 * 6 m/s^2 * (25 s)^2 = 1125 m. Adding the distance traveled during the initial 2 seconds, the total distance from point A to the point at which the patrolman overtakes the car is 1125 m + 4 km = 1125 m + 4000 m = 5125 m. However, the question asks for the distance from point A, so we subtract the initial distance traveled by the car (4 km) to get the final answer of 5125 m - 4000 m = 1125 m.Rate this question:
- 42.
A point mass of 1 kg collides elastically with a stationary point mass of 5 kg. After their collision, the 1 kg mass reverses its direction and moves with a speed of 2 ms−1. Which of the following statement(s) is (are) correct for the system of these two masses?
- A.
Total momentum of the system is 3 kg ms−1
- B.
Momentum of 5 kg mass after collision is 4 kg ms−1
- C.
Kinetic energy of the centre of mass is 0.80 J
- D.
Total kinetic energy of the system is 4J
Correct Answer
A. Total momentum of the system is 3 kg ms−1Explanation
The total momentum of a system is conserved in an elastic collision. Before the collision, the 1 kg mass has a momentum of 1 kg m/s in one direction, and the 5 kg mass has a momentum of 0 kg m/s since it is stationary. After the collision, the 1 kg mass reverses its direction and has a momentum of -1 kg m/s, while the 5 kg mass gains a momentum of 4 kg m/s in the opposite direction. Adding these momenta together, we get a total momentum of 3 kg m/s in the opposite direction of the initial momentum. Therefore, the statement "Total momentum of the system is 3 kg m/s" is correct.Rate this question:
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- 43.
A student uses a simple pendulum of exactly 1m length to determine g, the acceleration due to gravity. He uses a stop watch with the least count of 1 sec for this and records 40 seconds for 20 oscillations. For this observation, which of the following statement(s) is (are) true?
- A.
Error in measuring T, the time period, is 0.04 seconds
- B.
Error in measuring T, the time period, is 1 second
- C.
Percentage error in the determination of g is 5%
- D.
Percentage error in the determination of g is 2.5%
Correct Answer
C. Percentage error in the determination of g is 5%Explanation
The student measures the time period of the pendulum to be 40 seconds for 20 oscillations. Since one oscillation is half of the time period, the time period for one oscillation is 2 seconds. The error in measuring the time period is given as 0.04 seconds. To calculate the percentage error, we divide the error by the measured value and multiply by 100. In this case, the error is 0.04 seconds and the measured value is 2 seconds, so the percentage error is (0.04/2) * 100 = 2%. Therefore, the statement "Percentage error in the determination of g is 5%" is incorrect.Rate this question:
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- 44.
Convert 1C3 hexadecimal to decimal
- A.
451
- B.
113
- C.
453
Correct Answer
A. 451Explanation
To convert a hexadecimal number to decimal, each digit of the hexadecimal number is multiplied by the corresponding power of 16 and then added together. In this case, 1C3 can be broken down as follows: 1 * 16^2 + 12 * 16^1 + 3 * 16^0 = 256 + 192 + 3 = 451. Therefore, the decimal equivalent of 1C3 is 451.Rate this question:
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Mar 22, 2023Quiz Edited by
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Mar 04, 2015Quiz Created by
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