List of top Physics Questions asked in KEAM

The $Q$ factor for a damped oscillator is given by the

A thin circular ring of mass $m$ and radius $R$ is rotating about its axis perpendicular to the plane of the ring with a constant angular velocity $\omega$. Two point particles each of mass $M$ are attached gently to the opposite ends of a diameter of the ring. The ring now rotates with an angular velocity $\omega/2$. Then, the ratio $m/M$ is

The magnetic induction field has the dimensions of

Two particles of mass $m$ and $2m$ have their position vectors as a function of time as $\vec{r}_1(t)=t\hat{i}-t^3\hat{j}+2t^2\hat{k}$ and $\vec{r}_2(t)=t\hat{i}-t^3\hat{j}-t^2\hat{k}$ respectively (where $t$ is the time). Which one of the following graphs represents the path of the centre of mass

Two planets A and B have the same average density. Their radii $R_A$ and $R_B$ are such that $R_A : R_B = 3:1$. If $g_A$ and $g_B$ are the acceleration due to gravity at the surfaces of the planets, then $g_A : g_B$ equals

From a circular card board of uniform thickness and mass M, a square disc of maximum possible area is cut. If the moment of inertia of the square with the axis of rotation at the centre and perpendicular to the plane of the disc is $\frac{Ma^2}{6}$, the radius of the circular card board is

The length is measured using a vernier system whose main scale is 30 cm long with 600 divisions. If 19 divisions of the main scale coincide with 20 divisions of the vernier scale, then its least count is

A particle of mass $m$ is moving along the $x$-axis under the potential $V(x)=\frac{kx^2}{2}+\frac{\lambda}{x}$, where $k$ and $\lambda$ are positive constants. The particle is slightly displaced from its equilibrium position. The particle oscillates with the angular frequency $\omega$ given by

The period of oscillation of a simple pendulum is given by $T = 2\pi\sqrt{\frac{L}{g}}$, where $L$ is the length of the pendulum and $g$ is the acceleration due to gravity. The length is measured using a meter scale which has 2000 divisions. If the measured value of $L$ is 50 cm, the accuracy in the determination of $g$ is 1.1% and the time taken for 100 oscillations is 100 seconds, what should be the resolution of the clock (in milliseconds)?

The one-dimensional motion of a point particle is shown in the figure. Select the correct statement:

An alternating voltage $V=V_0\sin\omega t$ is applied across a circuit and as a result, a current $I=I_0\sin\left(\omega t+\frac{\pi}{2}\right)$ flows in it. The power consumed per cycle is

An electromagnetic wave of intensity $I$ is incident on a non-reflecting surface. If $C$ is the speed of light in free space, then, the ratio $\frac{I}{C}$ is same as

In the given circuit P and Q form the inputs. The output $Y$ is

A radio transmitter sends out 60 W of radiation. Assuming that the radiation is uniform on a sphere with the transmitter at its centre, the intensity (in W/m\(^2\)) of the wave at a distance 12 km is

A satellite is orbiting the earth in a circular orbit of radius R. Which one of the following statements is true ?

Consider a system of gas of a diatomic molecule in which the speed of sound at $0^\circ\text{C}$ is 1260 $\text{ms}^{-1}$. Then, the molecular weight of the gas is (Given the gas constant $R=8.314\,\text{J mol}^{-1}\text{K}^{-1}$)

The magnitude of a magnetic field at the centre of a circular coil of radius R, having N turns and carrying a current I can be doubled by changing

A prism is made up of material of refractive index $\sqrt{2}$. The angle of the prism is $A$. If the angle of minimum deviation is equal to the angle of the prism, the value of $A$ is

If the emission rate of blackbody at $0^\circ\text{C}$ is $R$ then, the rate of emission at $273^\circ\text{C}$ is

For any material, if R, T and A represent the reflection coefficient, transparent coefficient and absorption coefficient respectively, then, for a blackbody which one of the following is true ?

Consider a cylindrical conductor of length $L$ and area of cross section $A$. The specific conductivity varies as $\sigma(x)=\sigma_0\frac{L}{\sqrt{x}}$ where $x$ is the distance along the axis of the cylinder from one of its ends. The resistance of the system along the cylindrical axis is

What is the minimum thickness (in nm) of a soap film ($n = 1.3$) that results in constructive interference in reflected light if the film is illuminated with light whose wavelength in free space is 620 nm?

The electrical conductivity of a metal is

The 6 V Zener diode shown in figure has negligible resistance and a knee current of 5 mA. The minimum value of $R$ (in $\Omega$) so that the voltage across it does not fall below 6 V is

A 2 MeV neutron is emitted in a fission reactor. If it loses half of its kinetic energy in each collision with a moderator atom, how many collisions must it undergo to achieve thermal energy of 0.039 eV?