List of top Physics Questions

A body of mass 1 kg is suspended from a spring of force constant \( 600 \, \text{N m}^{-1} \). Another body of mass 0.5 kg moving vertically upwards hits the suspended body with a velocity of \( 3 \, \text{m s}^{-1} \) and embedded in it. The amplitude of motion is
A crane of efficiency 80% is used to lift 8000 kg of coal from a mine of depth 108 m. If the time taken by the crane to lift the coal is one hour, then the power of the crane (in kW) is (Acceleration due to gravity \( = 10 \, \text{m s}^{-2} \))
If the displacement 'x' of a body in motion in terms of time 't' is given by \(x = A\sin(\omega t + \theta)\), then the minimum time at which the displacement becomes maximum is
The number of significant figures in the simplification of \( \frac{0.501}{0.05}(0.312-0.03) \) is
If the magnitude of a vector \( \vec{p} \) is 25 units and its y-component is 7 units, then its x-component is
If a resistor of resistance \( 4 \Omega \), a capacitor of capacitive reactance \( 6 \Omega \) and an inductor of inductive reactance \( 9 \Omega \) are connected in series with an AC source, then the impedance of the circuit is:
If a wheel with 24 metallic spokes each \( 40 \) cm long is rotated with a speed of \( 180 \) rev/min in a plane normal to the horizontal component of Earth's magnetic field, the emf induced between the axle and the rim of the wheel is \( E \). If the number of spokes is made \( 12 \) and the wheel is rotated with a speed of \( 90 \) rev/min in the same field, the induced emf is:
The ratio of the magnitudes of the electric field and \( 10^8 \) times the magnetic field of a plane electromagnetic wave is:
A long straight wire of circular cross-section of radius \( a \) is carrying a steady current. The current is distributed uniformly across the cross-section of the wire. The ratio of the magnetic fields at points \( 0.5a \) and \( 1.5a \) from the centre of the wire is:
If a charged particle enters a uniform magnetic field normally with certain velocity, then the time period of revolution of the particle:
The capacitance of a spherical capacitor is \( 100 \) pF. If the spacing between the two spheres is \( 1 \) cm, then the radius of the inner sphere of the capacitor is:
In a closed organ pipe, the number of nodes formed in fifth and ninth harmonics are respectively:
The internal energy of one mole of a rigid diatomic gas at absolute temperature \( T \) 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 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:
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
The ratio of the wavelengths of the first Lyman line and the second Balmer line of hydrogen atom 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
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
A resistor of \(450 \, \Omega\) and an inductor are connected in series to an ac source of frequency \( \frac{75}{\pi} \, \text{Hz} \). If the power factor of the circuit is 0.6, then the inductance connected in the circuit 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
If current of 80 A is passing through a straight conductor of length 10 m, then the total momentum of electrons in the conductor is (mass of electron \( = 9.1 \times 10^{-31} \) kg and charge of electron \( = 1.6 \times 10^{-19} \) C)
The length and area of cross-section of a copper wire are respectively 30 m and \( 6 \times 10^{-7} \, \text{m}^2 \). If the resistivity of copper is \( 1.7 \times 10^{-8} \, \Omega \, \text{m} \), then the resistance of the wire is