List of top Physics Questions

An electron accelerated through potential difference \(V\) passes through a uniform transverse magnetic field and experiences a force \(F\). If the accelerating potential is increased to \(2V\), the electron in the same magnetic field will experience a force

Two springs of spring constants \(K\) and \(2K\) are stretched by the same force. If \(W_1\) and \(W_2\) are the energies stored in them respectively, then

A Fraunhofer diffraction pattern due to a single slit of width \(0.3\,\text{mm}\) is obtained on a screen placed at a distance of \(3\,\text{m}\) from the slit. The first minima lie at \(5.5\,\text{mm}\) on either side of the central maximum on the screen. The wavelength of light used is

A particle performs S.H.M. with amplitude \( A \). Its speed is tripled at the instant when it is at a distance of \( \frac{2A}{3} \) from the mean position. The new amplitude of the motion is

One end of thick horizontal copper wire of length \(2L\) and radius \(2R\) is welded to the end of another thin horizontal copper wire of length \(L\) and radius \(R\). When they are stretched by applying the same force at the two ends, the ratio of the elongation in the thick wire to that in the thin wire is

If \( \vec{A} = 3\hat{i} - 2\hat{j} + \hat{k} \), \( \vec{B} = \hat{i} - 3\hat{j} + 5\hat{k} \) and \( \vec{C} = 2\hat{i} + \hat{j} - 4\hat{k} \) form a right angled triangle, then out of the following which one is satisfied?

The non-zero potential difference across diode \(D_1\) and that across diode \(D_2\) are equal in the circuit shown in the figure (both diodes are identical in characteristics)

A donor impurity results in

A mass \( m \) is tied to one end of a spring and whirled in a horizontal circle with constant angular velocity. The elongation in the spring is 1 cm. If the angular speed is doubled, the elongation in the spring is 6 cm. The original length of the spring is

In non-uniform circular motion, the ratio of tangential to radial acceleration is
\(\textit{(r = radius, \( \alpha \) = angular acceleration, V = linear velocity)}\)

A body of mass 2 kg is acted upon by two forces, each of magnitude 1 N and inclined at \( 60^\circ \) with each other. The acceleration of the body in \( \text{m/s}^2 \) is
\(\textit{(cos 60° = 0.5)}\)

A simple pendulum of length \( L \) has mass \( m \) and it oscillates freely with amplitude \( A \). At extreme position, its potential energy is
\(\textit{(g = acceleration due to gravity)}\)

A particle of mass \( m \) is performing U.C.M. along a circle of radius \( r \). The relation between centripetal acceleration \( a \) and kinetic energy \( E \) is given by

A large open tank containing water has two holes to its wall. A square hole of side \( a \) is made at a depth \( y \) and a circular hole of radius \( r \) is made at a depth \( 16y \) from the surface of water. If equal amount of water comes out through both the holes per second, then the relation between \( r \) and \( a \) will be

A batsman hits a ball of mass 0.2 kg straight towards the bowler without changing its initial speed of 6 m/s. What is the impulse imparted to the ball?

The resultant of two vectors \( \vec{A} \) and \( \vec{B} \) is \( \vec{C} \). If the magnitude of \( \vec{B} \) is doubled, the new resultant vector becomes perpendicular to \( \vec{A} \). Then the magnitude of \( \vec{C} \) is

A block of mass \( M \) is moving on rough horizontal surface with momentum \( P \). The coefficient of friction between the block and surface is \( \mu \). The distance covered by the block before it stops is

A square frame of each side \( L \) is dipped in a soap solution and taken out. The force acting on the film formed is \( T = \) surface tension of soap solution

A particle performs simple harmonic motion with period of 3 second. The time taken by it to cover a distance equal to half the amplitude from mean position is

The ratio of energies of photons produced due to transition of electron of hydrogen atom from its (i) second to first energy level and (ii) highest energy level to 2\(^\text{nd}\) level is respectively

If the angle of dip at places A and B are 30° and 45° respectively, the ratio of horizontal component of earth's magnetic field at A to that at B will be

A circular coil of radius \( R \) has a resistance of 40\( \Omega \). Figure shows two points \( P \) and \( Q \) on the circumference separated by a distance \( \frac{\pi R}{2} \), which are connected to a 16 V battery with internal resistance of 0.5 \( \Omega \). What is the value of current \( I \) flowing through the circuit?