List of top Physics Questions

Radius of gyration of a thin uniform rod of length \( L \) about an axis passing through its centre and perpendicular to its length is:
If the pressure on a body is increased from \( 200 \) kPa to \( 250 \) kPa, the volume of the body decreases by \( 0.25% \). The compressibility of the material of the body (in \( m^2 N^{-1} \)) is:
A particle is executing simple harmonic motion with amplitude \( A \). At a distance \( x \) from the mean position, when the particle is moving towards the extreme position, it receives a blow in the direction of motion that instantaneously doubles its velocity. The new amplitude of the particle is:
A mercury drop of radius \( 1 \) cm is divided into \( 10^6 \) droplets of equal size. If the surface tension of mercury is \( 35 \times 10^{-3} \) N/m, then the change in surface energy in the process is:
A mass of \( 6 \times 10^{24} \) kg is to be compressed in the form of a solid sphere such that the escape velocity from its surface is \( 3 \times 10^5 \) m/s. The radius of the sphere is:
A body of mass \( 4 \) kg attached to a spring of force constant \( 64 \) N/m executes simple harmonic motion on a frictionless horizontal surface. The time period of oscillation is:
A car of mass \( 2000 \) kg is accelerating from rest. If its engine is supplying constant power of \( 10 \) kW, then the velocity of the car at a time of \( 10 \) s is:
The angle of projection of a projectile whose path is shown in the given figure is:
The angle of projection of a projectile
If the tension in the horizontal wire shown in the figure is 30 N, then the weight \( W \) and tension in the wire \( OA \) are respectively:
tension in the horizontal wire
If the distance travelled by a freely falling body in the last but one second of its motion is 5 m, then the last second is:
If a particle is moving along a circle of radius \( r \) with constant speed \( v \), then the magnitude of the change in velocity when the particle moves from \( P \) to \( Q \), where \( PQ \) makes an angle \( \theta \) at the center of the circle is:
If the equation of motion of a projectile is \( Y = AX - B X^2 \), then the ratio of the maximum height reached and the range of the projectile is:
A body of mass \( M \) is moving with a uniform speed \( v \) on a frictionless horizontal surface under the influence of two forces \( F_1 \) and \( F_2 \) as shown in the figure. The net power of the system is:
Of the following, the pair of physical quantities not having the same dimensional formula is:
The ratio of the wavelengths of the first Lyman line and the second Balmer line of hydrogen atom is
The device used for voltage regulation is
Each nuclear fission of \( {}^{235}\text{U} \) releases 200 MeV of energy. If a reactor generates 1 MW power, then the rate of fission in the reactor is
When three NAND logic gates are connected as shown in the figure, then the logic gate equivalent to the circuit is
three NAND logic gates are connected
For transmitting a signal of frequency 1000 kHz, the minimum length of the antenna is
If the threshold wavelength of light for photoelectric emission to take place from a metal surface is \( 6250 \, \text{\AA} \), then the work function of the metal is (Planck's constant \( = 6.6 \times 10^{-34} \, \text{Js} \))
A metallic disc of radius 0.3 m is rotating with a constant angular speed of \( 60 \, \text{rad s}^{-1} \) in a plane perpendicular to a uniform magnetic field of \( 5 \times 10^{-2} \, \text{T} \). The emf induced between a point on the rim and the centre of the disc is
A short bar magnet of magnetic moment \( 10^4 \, \text{J T}^{-1} \) is free to rotate in a horizontal plane. The work done in rotating the magnet slowly from the direction parallel to a horizontal magnetic field of \( 4 \times 10^{-5} \, \text{T} \) to a direction \( 60^\circ \) to the direction of the field is
If the rms value of the electric field of electromagnetic waves at a distance of 3 m from a point source is \( 3 \, \text{N C}^{-1} \), then the power of the source is
In a wire of radius 1 mm, a steady current of 2 A uniformly distributed across the cross-section of the wire is flowing. Then the magnetic field at a point 0.25 mm from the centre of the wire is
The magnetic field at the centre of a current carrying circular coil of radius R is \( B_C \) and the magnetic field at a point on its axis at a distance R from its centre is \( B_A \). The value of \( \frac{B_C}{B_A} \) is