List of top Physics Questions

Consider a convex lens of focal length $f$. A point object moves towards the lens along its axis between $2f$ and $f$. If the speed of the object is $V_o$, then its image would move with speed $V_i$. Which of the following is correct?

A disc of radius $R_1$ having uniform surface density has a concentric hole of radius $R_2<R_1$. If its mass is $M$, the principal moments of inertia are

The plane of polarisation of a plane-polarised light rotates by $60^\circ$ after passing through a wave plate. The pass-axis of the wave plate is at an angle $\alpha$ with respect to the plane of polarisation of the incident light. The wave plate and $\alpha$ are

The equation of state for one mole of a non-ideal gas is given by $PV = A\left(1 + \dfrac{B}{V}\right)$, where the coefficients $A$ and $B$ are temperature dependent. If the volume changes from $V_1$ to $V_2$ in an isothermal process, the work done by the gas is

Consider an ensemble of thermodynamic systems, each of which is characterized by the same number of particles, pressure and temperature. The thermodynamic function describing the ensemble is

A rectangular loop of dimensions $l$ and $w$ moves with a constant speed $v$ through a region containing a uniform magnetic field $B$ directed into the paper and extending a distance of $4w$. Which of the following figures correctly represents the variation of emf $(\varepsilon)$ with the position $(x)$ of the front end of the loop?
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An ideal gas consists of three dimensional polyatomic molecules. The temperature is such that only one vibrational mode is excited. If $R$ denotes the gas constant, then the specific heat at constant volume of one mole of the gas at this temperature is

Three infinite plane sheets carrying uniform charge densities $-\sigma,\,2\sigma,\,3\sigma$ are placed parallel to the $xz$-plane at $y=a,\;3a,\;4a$, respectively. The electric field at the point $(0,2a,0)$ is

Let $T_g$ and $T_e$ be the kinetic energies of the electron in the ground and the third excited states of a hydrogen atom. According to the Bohr model, the ratio $T_g/T_e$ is

Two boxes A and B contain an equal number of molecules of the same gas. If the volumes are $V_A$ and $V_B$, and $\lambda_A$ and $\lambda_B$ denote respective mean free paths, then

A current $I$ flows through the sides of an equilateral triangle of side $a$. The magnetic field at the centroid is

The logic operation (OR, AND, NOR or NAND) carried out by the following circuit is

Nucleus of a radioactive material can undergo beta decay with half life of 4 minutes. Suppose beta decay starts with 4096 nuclei at $ t = 0 $, the number of nuclei left after 20 minutes would be

Match the entries in Group I (Mechanical system) with analogous quantities in Group II (Electrical system)
Group I Group II
P) Mass 1) Current
Q) Spring constant 2) Voltage
R) Displacement 3) Reciprocal capacitance
S) Velocity 4) Charge
5) Inductance

Which of the following statements is/are CORRECT regarding self-inductance of a long solenoid having cross sectional area $ A $, length $ l $, and having $ n $ turns per unit length filled with material of relative permeability $ \mu_r $?

If an optician prescribes a corrective lens of power -2.0 D, the required lens

The equivalent capacitance of the following assembly of capacitors is .......... $ \mu F $.

An ultrasound signal of frequency 50 KHz is sent vertically down into a medium. The signal gets reflected from a depth of 25 mm and returns to source 0.00005 seconds after it is emitted. The wavelength of the ultrasound signal in that medium is ............... cm.

The relationship between the applied force $ F(X) $ (in Newton) on a body and its displacement $ X $ (in metre) is given below. The total amount of work done in moving the body from $ X = 0 $ to $ X = 4 \, \text{m} $ is ............ Joule.

A 30 μF capacitor is connected to a 240 V, 50 Hz source. If the frequency of the source is changed from 50 Hz to 200 Hz, the capacitive reactance of the capacitor will

Which one of the following shows the CORRECT relationship among velocity of light in a medium ($ v $), permittivity of medium ($ \varepsilon $) and magnetic permeability of medium ($ \mu $)?

A displacement vector is a

During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute temperature. The ratio of $ \frac{C_p}{C_v} $ for the gas is

A metallic ball has a spherical cavity at its centre. If the ball is heated, what happens to the cavity?

The diagrammatic representation of a heat engine above shows which of the following?