Physics MCQs

Notes:
A concave lens is a type of lens that has a thinner center than edges, and it is sometimes called a diverging lens because it spreads out light rays that are parallel to its axis. The focal length of a lens is a measure of its ability to focus light, and it is defined as the distance from the lens to the point where the light rays converge. In the case of a concave lens with a power of -5D, the focal length would be equal to 1/5 of a meter, or 20 centimeters.

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The latent heat Latent heat is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process. It causes change in state or phase but not in temperature.

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Mach number refers to the ratio of the velocity of a fluid to the velocity of sound in that fluid, named after Ernst Mach (1838–1916), an Austrian physicist and philosopher. Speed of sound is Mach 1 speed.

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A cyclotron is a type of particle accelerator invented by Ernest O. Lawrence in 1929–1930 at the University of California, Berkeley, and patented in 1932. A cyclotron accelerates charged particles outwards from the center along a spiral path.

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Uniform speed means no acceleration. If there is no acceleration and the vehicle is moving with uniform speed; the stone will fall over you.

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To calculate the distance of the object from the source of sound based on the time taken for the echo, we can use the formula for distance traveled by sound:

Distance = (Speed of Sound × Time) / 2

The speed of sound in air at normal room temperature (20°C) is approximately 343 meters per second (m/s).

Given that the time taken in the echo is 5 seconds, we can plug the values into the formula:

Distance = (343 m/s × 5 s) / 2 Distance = 1715 meters / 2 Distance ≈ 857.5 meters

So, the approximate distance of the object from the source of sound is approximately 857.5 meters.

Notes:
When we press the top of bottle the pressure at top of the bottle decreases and hence, the velocity of liquid flow increases. Bernoulli’s Principle states that an increase in the speed of a fluid produces a decrease in pressure and that a decrease in the speed of a fluid produces an increase in pressure. The principle states that the total energy of a moving fluid remains constant at all times.

Notes:
C.V Raman discovered the Inelastic scattering of light by molecules in 1928, also named as ‘Raman effect’ Raman scattering is the inelastic scattering of a photon by molecules which are excited to higher vibrational or rotational energy levels. He was the first Indian Physicist to win the Nobel Prize for Physics in 1930. C.V Raman has also been bestowed with the Bharat Ratna Award.

Notes:
The S.I. unit for Luminous Intensity is candela. The symbol used for candela is cd. Mole is the S.I unit for Quantity of Matter ampere is the S.I unit for Electric Current. Weber is the S.I unit for Magnetic Flux Luminous Intensity is the amount of light that a point source radiates in a given direction

Notes:
The physical quantities which have both magnitude and direction are called as Vector quantities. Some examples of Vector quantities: Acceleration, Velocity, Torque, Displacement, Gravitational Intensity, Force.