Online Physics Quiz 2020 For B. Sc. Sem VI Organized By Department Of Physics, Kamla Nehru MahaVIdyalaya, NaGPur

According to the theory of relativity, the relativistic mass of an object is given by the equation m = m0 / sqrt(1 - v^2/c^2), where m0 is the rest mass of the object, v is its velocity, and c is the speed of light. This equation shows that as the velocity of an object approaches the speed of light, its relativistic mass increases. This is due to the time dilation and length contraction effects predicted by relativity, which cause an increase in mass as an object's velocity increases.

The correct answer is Electroencephalogram or EEG. This is because the study and analysis of signals arising due to electrical activity of the brain is specifically known as EEG. This technique involves placing electrodes on the scalp to measure and record the electrical activity of the brain, which can help diagnose various neurological disorders and study brain function. Electrocardiogram (ECG) is used to measure the electrical activity of the heart, while Electro-orthogram (EOG) and Electro-kidneygram (EKG) are not valid terms in the context of studying brain signals.

Sir Ernest Lawrence is the correct answer because he is credited with inventing the cyclotron. Lawrence was an American physicist who developed the cyclotron in the 1930s. The cyclotron is a type of particle accelerator that uses a magnetic field to accelerate charged particles in a spiral path. Lawrence's invention revolutionized the field of nuclear physics and paved the way for further advancements in particle physics research.

The correct answer is NA = sin θa. The numerical aperture (NA) is a measure of the light-gathering ability of a fiber. It is determined by the acceptance angle (θa) of the fiber. The expression NA = sin θa indicates that the numerical aperture is equal to the sine of the acceptance angle. This means that the NA increases as the acceptance angle increases, allowing the fiber to collect more light.

The NAND gate is also known as a universal logic gate because it can be used to implement any other logic gate. It can perform the functions of AND, OR, and NOT gates by simply combining multiple NAND gates. This makes it a versatile and essential component in digital circuit design.

Uranium is used as fuel in a nuclear reactor. Uranium is a naturally occurring element that can undergo nuclear fission, releasing a large amount of energy. This energy is harnessed in a nuclear reactor to generate electricity. Plutonium can also be used as fuel in certain types of reactors, but uranium is the most commonly used fuel in nuclear power plants. Radium is not used as fuel in nuclear reactors.

Henri Becquerel discovered radioactivity. He made this discovery in 1896 while studying the effects of uranium salts on photographic plates. Becquerel accidentally left a uranium compound near the plates and noticed that they were still exposed, even though they were kept in a dark drawer. This led him to conclude that uranium emitted a form of radiation that could penetrate matter and affect photographic plates. Becquerel's discovery laid the foundation for further research on radioactivity by other scientists, including Marie and Pierre Curie.

An alpha particle is the correct answer because a helium nucleus consists of two protons and two neutrons, which is the same composition as an alpha particle. Beta particles are high-energy electrons or positrons, and gamma particles are high-energy photons. None of the above options accurately describe a helium nucleus.

The Roman Number System is not a positional number system because it does not follow the concept of place value. In a positional number system, the value of a digit depends on its position in the number. However, in the Roman Number System, the value of a symbol depends on its specific symbol, and there is no positional significance.

Gamma radiation is more penetrating and energetic compared to alpha and beta radiations. Alpha radiation consists of helium nuclei and is the least penetrating due to its large size and positive charge. Beta radiation consists of fast-moving electrons or positrons and is more penetrating than alpha radiation but less penetrating than gamma radiation. Gamma radiation consists of high-energy photons and is the most penetrating and energetic of the three types of radiation.

The correct answer is arterial depolarization. In a normal ECG, the P wave represents the depolarization of the atria, specifically the contraction of the atrial muscle. This electrical activity spreads through the atria, causing them to contract and pump blood into the ventricles. The depolarization of the atria is an important step in the cardiac cycle and is reflected as the P wave on an ECG.

Ultrasonography is a medical imaging technique that uses high frequency sound waves and their echoes. The high frequency of the sound waves allows for detailed imaging of internal organs and structures. The sound waves are emitted from a transducer and then bounce back as echoes when they encounter different tissues or structures in the body. These echoes are then used to create a visual representation of the internal structures, which can be used for diagnostic purposes.

Fibre optical cables work on the principle of total internal reflection. This phenomenon occurs when light traveling through a medium with a higher refractive index encounters a boundary with a medium of lower refractive index at an angle greater than the critical angle. Instead of refracting out of the medium, the light reflects back inside, allowing it to travel through the cable without significant loss of signal. Total internal reflection is crucial for transmitting data through fibre optic cables, as it ensures that the light signals remain confined within the cable and can travel long distances without significant degradation.

Modulation is the process by which some characteristic property of a high frequency wave, such as amplitude, frequency, or phase, is varied in accordance with the instantaneous value of a signal. This allows the signal to be encoded onto the carrier wave, enabling it to be transmitted over long distances and received by a receiver. Modulation is commonly used in various communication systems, such as radio and television broadcasting, to ensure the accurate transmission and reception of signals.

In the sun, nuclear fusion takes place. This is a process where two or more atomic nuclei combine to form a larger nucleus, releasing a large amount of energy in the process. In the sun's core, hydrogen atoms combine to form helium through nuclear fusion, releasing vast amounts of energy in the form of light and heat. This process is what powers the sun and allows it to emit heat and light.

The output voltage of an Op-Amp as an integrator is determined by the input voltage and the feedback capacitor. The input voltage is integrated over time by the capacitor, resulting in an output voltage that is proportional to the integral of the input voltage. This is achieved by connecting the input voltage to the inverting terminal of the Op-Amp and the feedback capacitor between the output and the inverting terminal. The integration function of the Op-Amp can be represented by the equation Vout = -1/(Rf*Cf) * ∫(Vin) dt, where Vout is the output voltage, Vin is the input voltage, Rf is the feedback resistor, Cf is the feedback capacitor, and ∫(Vin) dt represents the integral of the input voltage over time.

The principle of the Geiger Muller counter is based on the ionization of gas when nuclear radiations pass through it. This means that when the radiations interact with the gas molecules, they cause the gas atoms to lose electrons, creating positively charged ions. The Geiger Muller counter detects these ionizations by using a gas-filled chamber and measuring the electrical current produced when the ions move towards the electrodes. This principle allows the Geiger Muller counter to effectively detect and measure nuclear radiation levels.

The cardiovascular system is responsible for supplying oxygenated blood to different parts of the body and collecting deoxygenated blood from the body. It consists of the heart, blood vessels, and blood. The heart pumps the blood, while the blood vessels act as the transportation network, carrying the blood to various organs and tissues. The cardiovascular system plays a crucial role in maintaining the body's overall function and ensuring the delivery of nutrients and oxygen to all cells.

An ideal Op-Amp is defined as having infinite voltage gain. This means that the output voltage of the Op-Amp will be infinitely larger than the input voltage. In practical terms, this means that the Op-Amp can amplify very small input signals to a much larger output signal. This characteristic makes the Op-Amp a versatile and powerful tool in many electronic applications.

The modulation index of FM is given by the ratio of the frequency deviation to the modulating frequency. The frequency deviation refers to the maximum change in the carrier frequency caused by the modulation, while the modulating frequency is the frequency of the modulating signal. The modulation index represents the extent of frequency variation in the carrier signal due to the modulation.

Gamma-ray photons have no mass and no electric charge. Gamma rays are a form of electromagnetic radiation, just like visible light, but with much higher energy. Photons are the particles that make up electromagnetic radiation, and they have no mass and no electric charge. This means that gamma-ray photons are neutral and do not interact with electric or magnetic fields. They can travel long distances through space and penetrate matter easily due to their lack of charge and mass.

The outer optical material surrounding the core of a fibre optic cable is called cladding. Cladding is designed to have a lower refractive index than the core, which allows it to reflect the light back into the core through total internal reflection. This ensures that the light signal travels along the core without significant loss of signal strength. The cladding acts as a protective layer for the core, preventing external interference and maintaining the integrity of the optical signal.

DeMorgan's theorems state that the complement of the product of two variables is equal to the sum of the complements of the individual variables, and the complement of the sum of two variables is equal to the product of the complements of the individual variables. These theorems are used in Boolean algebra to simplify logical expressions and manipulate logic gates. Therefore, the correct answer is DeMorgan's theorems.

According to special relativity, all of the listed physical properties (length, energy, and time) are dependent on the observer's speed. This is because special relativity states that the laws of physics are the same for all observers in uniform motion relative to each other. As an observer's speed approaches the speed of light, these properties can change and are perceived differently by different observers. Therefore, all of these physical properties are influenced by the observer's speed.

A half adder is a digital circuit that adds two single-bit binary numbers and has two inputs, one for each bit. It produces a sum and a carry as outputs. On the other hand, a full adder is a digital circuit that adds three single-bit binary numbers, including a carry from a previous addition. It has three inputs, one for each bit and an additional carry input. It produces a sum and a carry as outputs. Therefore, the correct answer is "Half adder has two inputs while full adder has three inputs."

In a nuclear fusion reaction, two light nuclei of low mass combine to form a heavier nucleus. This process releases a large amount of energy. This is different from nuclear fission, where a heavy nucleus is split into two lighter nuclei. Fusion reactions are the process that powers the sun and other stars, and scientists are trying to replicate this process on Earth as a potential source of clean and abundant energy.

Attenuation refers to the reduction in the intensity or power of a light signal as it travels through a fiber optic cable. Therefore, the correct answer is "The loss in signal power."

The correct answer is m = Es / Ec. The modulation factor in amplitude modulation is defined as the ratio of the peak voltage of the signal wave (Es) to the peak voltage of the carrier wave (Ec). This ratio determines the extent to which the carrier wave is modulated by the signal wave. A modulation factor greater than 1 indicates overmodulation, while a value less than 1 indicates undermodulation.

In modulation, the frequency of the carrier signal is higher compared to the signal wave. Modulation involves superimposing the signal onto the carrier wave, and the carrier wave must have a higher frequency to carry the information efficiently. This allows for the transmission of the signal over long distances without significant loss or interference. Therefore, the correct answer is "High."

The Geiger Nuttal law states that the more energetic alpha particles are emitted by short-lived isotopes of a radioactive element compared to long-lived ones. This law provides a correlation between the half-life of a radioactive isotope and the energy of the alpha particles it emits. The law suggests that as the half-life increases, the energy of the emitted alpha particles decreases. Therefore, the given statement aligns with the Geiger Nuttal law.

Negative feedback is a technique used in amplifiers to reduce the voltage gain. It involves feeding back a portion of the output signal to the input in such a way that it opposes the input signal. This helps in stabilizing the amplifier's gain and reducing distortion. By introducing negative feedback, the overall gain of the amplifier is reduced, resulting in a more controlled and accurate amplification of the input signal.

The Slew Rate is the correct answer because it refers to the maximum rate of change in the output voltage per unit time in an operational amplifier (Op-Amp). It measures how quickly the output voltage can respond to changes in the input signal. A higher slew rate indicates a faster response time and better performance of the Op-Amp.

The Michelson-Morley experiment was conducted to detect any possible motion of the Earth relative to the ether. The ether was a hypothetical substance believed to fill the empty space and serve as a medium for the propagation of light waves. The experiment aimed to measure the interference patterns of light waves traveling in different directions to determine if there was any variation caused by the Earth's motion through the ether. However, the experiment yielded unexpected results, showing no evidence of the Earth's motion relative to the ether. This experiment played a crucial role in the development of the theory of relativity.

In fiber optic cables, the refractive index of the cladding is always less than the refractive index of the core. This is because the cladding is designed to have a lower refractive index in order to create total internal reflection within the core. This ensures that the light signals transmitted through the core are effectively contained and guided along the fiber without significant loss or dispersion.

not-available-via-ai

In a nuclear fission reaction, a heavy nucleus is fragmented into lighter ones. This process releases a significant amount of energy.

The acceptance angle refers to the maximum angle at which light can enter a fiber optic cable and still be transmitted efficiently. This angle is determined by the refractive index of the fiber and the surrounding medium. If the angle of incidence exceeds the acceptance angle, the light will not be effectively transmitted and will experience significant losses. Therefore, the acceptance angle plays a crucial role in ensuring optimal transmission of light through fiber optic cables.

Transistors can be used to construct logic gate circuits. Transistors are semiconductor devices that can amplify or switch electronic signals and are commonly used in digital circuits. They can be used to create logic gates such as AND, OR, and NOT gates, which are the building blocks of digital systems. By combining transistors in different configurations, complex logic circuits can be constructed to perform various computational tasks. Therefore, transistors are a suitable option for constructing logic gate circuits.

The voltage gain of an inverting amplifier is determined by the ratio of the output resistance (R0) to the input resistance (R1), with a negative sign. This means that the correct answer is -R0 / R1.

In amplitude modulation, the process of varying the amplitude of a carrier signal with the input signal, the frequency and phase of the carrier signal remain constant. Only the amplitude of the carrier signal is modified to carry the information.

Biophysics is the branch of science that focuses on the application of physical principles to understand biological systems. It involves studying the physical properties and processes that occur in living organisms, such as the mechanics of cell membranes, the behavior of proteins, and the forces involved in DNA replication. By investigating the physical aspects of biological phenomena, biophysicists aim to gain a deeper understanding of how living organisms function at a molecular level. Therefore, the answer "Physical principles involved in biology" accurately describes the subject matter of biophysics.

According to Einstein's Special Theory of Relativity, laws of physics can be formulated based on the Inertial Frame of Reference. This means that the laws of physics remain the same in frames of reference that are not accelerating or experiencing any net force. Inertial frames are important because they provide a consistent and reliable framework for understanding the behavior of objects and phenomena in the universe.

The hexadecimal number (E)16 is equivalent to the binary number 1110. In the binary system, each digit represents a power of 2, starting from the rightmost digit as 2^0. Therefore, starting from the leftmost digit, the first digit represents 2^3, the second digit represents 2^2, the third digit represents 2^1, and the last digit represents 2^0. Adding up the values of these powers of 2 that correspond to the digits in the binary number gives us the decimal equivalent of the hexadecimal number. In this case, 1*2^3 + 1*2^2 + 1*2^1 + 0*2^0 = 8 + 4 + 2 + 0 = 14, which is represented as E in hexadecimal.

The Hartley oscillator is commonly used in radio receivers. This oscillator circuit generates a continuous wave signal that can be used for tuning and amplifying radio frequency signals. It is specifically designed for use in radio receivers to provide a stable and reliable oscillating signal for proper functioning of the receiver.

During beta decay, a neutron in the nucleus transforms into a proton and emits an electron (beta particle) and an antineutrino. The antineutrino is a neutral particle with extremely low mass and interacts weakly with matter. It carries away some of the energy and angular momentum from the decay process. Therefore, the correct answer is neutrinos, as they are emitted during beta decay along with electrons.

Neutrons are not accelerated by a cyclotron because they have no charge. Cyclotrons work by using an electric field to accelerate charged particles, such as electrons or protons, in a circular path. Since neutrons are electrically neutral, they do not experience a force in an electric field and therefore cannot be accelerated by a cyclotron.

There is only one inductor in the tank circuit of Colpitt's oscillator. The tank circuit is a combination of an inductor and a capacitor that determines the frequency of oscillation. In the case of Colpitt's oscillator, the tank circuit consists of a single inductor and a capacitor. Therefore, the correct answer is 1.

The term "space-time reference" refers to a frame of reference that includes both spatial coordinates (x, y, z) and time (t). This concept is a fundamental aspect of Einstein's theory of relativity, which states that space and time are interconnected and should be considered together as a four-dimensional continuum. In a space-time reference frame, the position and motion of objects can be described using all four coordinates, allowing for a more complete understanding of their behavior in relation to each other.

The disadvantage of AM is excess bandwidth and high transmitted power. This means that AM requires a larger bandwidth to transmit the same amount of information compared to other modulation techniques. Additionally, AM also requires a higher transmitted power, which can lead to increased interference and reduced efficiency in the transmission.

The equation E = mc^2, derived by Albert Einstein, states that energy (E) and mass (m) are interchangeable and can be converted into each other. This equation shows that energy and mass are not separate entities but rather different forms of the same thing.