List of top Physics Questions

Two identical parallel plate air capacitors are connected in series to a battery of e.m.f. \( V \). If one of the capacitors is inserted in liquid of dielectric constant \( K \), then potential difference of the other capacitor will become
A circular coil of radius \( R \) is carrying a current \( I_1 \) in anticlockwise sense. A long straight wire is carrying current \( I_2 \) in the negative direction of x-axis. Both are placed in the same plane and the distance between the centre of coil and straight wire is \( d \). The magnetic field at the centre of coil will be zero for the value of \( d \) equal to
A body performing simple harmonic motion has potential energy \(P_1\) at displacement \(x_1\). Its potential energy is \(P_2\) at displacement \(x_2\). The potential energy \(P\) at displacement \((x_1 + x_2)\) is
When a beam of unpolarised monochromatic light is incident on a plane glass plate at a polarising angle, which one of the following statements is correct?
One mole of a diatomic gas does a work $\frac{Q{3}$, when the amount of heat supplied is $Q$. In this process, the molar heat capacity of the gas is}
A metal rod of Young’s modulus $Y$ and coefficient of linear expansion $\alpha$ has its temperature raised by $\Delta \theta$. The linear stress to prevent the expansion of rod is ($L$ and $\ell$ are original length of rod and expansion respectively)
When a ray of light is refracted from one medium to another, then the wavelength changes from 6000 Å to 4000 Å. The critical angle for the interface will be:
On mixing a highly soluble impurity in water, the surface tension \(T\) and angle of contact \(\theta\)
A body slides down a smooth inclined plane having angle \( \theta \) and reaches the bottom with velocity \( v \). If a body is a sphere then its linear velocity at the bottom of the plane is
The ratio of energy required to raise a satellite of mass \( m \) to a height \( h \) above the earth's surface to that required to put it into the orbit at same height is
Two rings of radius \( R \) and \( nR \) made of the same material have the ratio of moment of inertia about an axis passing through their centre and perpendicular to the plane as \( 1 : 8 \). The value of \( n \) is (mass per unit length is constant).
Rate of radiation by a black body is $R$ at temperature $T$. Another body has the same area but emissivity is $0.2$ and temperature is $3T$. Its rate of radiation is
Two wires 'A' and 'B' of equal lengths are connected in left and right gaps of a meter bridge, respectively. The null point is obtained at 40 cm from the left end. Diameters of the wires 'A' and 'B' are in the ratio 3:1, the ratio of specific resistance of 'A' to that of 'B' is
If \( \mathbf{A} = \hat{i} + 12 \hat{j} + \hat{k} \) and \( \mathbf{B} = 2\hat{i} - a\hat{j} + \hat{k} \) are perpendicular to each other, then what will be the value of \( a \)?
When a certain length of wire is turned into one circular loop, the magnetic induction at the centre of the coil due to current \(I\) is \(B_1\). If the same wire is turned into four loops to make a circular coil, the magnetic induction at the centre of this coil is \(B_2\) for the same current. Then the relation between \(B_2\) and \(B_1\) is
The moment of inertia of a ring about an axis passing through its centre and perpendicular to its plane is \(I\). It is rotating with angular velocity \(\omega\). Another identical ring is gently placed on it so that their centres coincide. If both the rings rotate about the same axis, then loss in kinetic energy is
An iron rod is placed parallel to the magnetic field of intensity 2000 \( A/m \). The magnetic flux through the rod is \( 6 \times 10^{-4} \, Wb \) and its cross-sectional area is \( 3 \, cm^2 \). The magnetic permeability of the rod in \( \frac{Wb}{A \cdot m} \) is
A wire has a length of 2 m and resistance of \(10\,\Omega\). It is connected in series with a resistance of \(990\,\Omega\) and a cell of e.m.f. 2 V. The potential gradient along the wire will be
In the equation \( P = \frac{C+S}{D} \), \( P \) and \( S \) represent pressure and distance respectively. The dimensions of \( \frac{P}{D} \) are
Using Bohr’s quantization condition, what is the rotational energy in the second orbit for a diatomic molecule? (I = moment of inertia of diatomic molecule, \( h \) = Planck’s constant)
In series LCR circuit, resistance is 18 \( \Omega \) and impedance is 33 \( \Omega \). An r.m.s. voltage of 220 V is applied across the circuit. The true power consumed in a.c. circuit is
Binding energy of a revolving satellite at height \(h\) is \(3.5\times10^8\,\text{J}\). Its potential energy is
The 3rd overtone of a closed organ pipe is in unison with 3rd overtone of an open pipe. The ratio of the length of the closed pipe to the length of open pipe is
A progressive wave of frequency \( 50\,\text{Hz} \) is travelling with velocity \( 350\,\text{m s}^{-1} \) through a medium. The change in phase at a given point in a time interval of \( 0.01\,\text{s} \) is
The motion of a rocket in upward direction with high speed is based on the principle of conservation of