List of top Physics Questions

The work done in displacing a particle from $y=a$ to $y = 2a$ by a force $F = -\frac{K}{y^2}$ acting along y-axis is
A truck of mass 8 ton is carrying a block of mass 2 ton. If a breaking force of 25 kN is applied on the truck, then the frictional force acting on the block is (Coefficient of static friction between the block and the truck is 0.3)
A ball projected at an angle of 45$^\circ$ with the horizontal crosses two points at equal heights separated by a distance at times 2 s and 8 s respectively. The horizontal distance between the two points is (Acceleration due to gravity = 10 ms$^{-2}$)
A person wearing a parachute jumps off a plane from a height of 2 km from the ground and falls freely for 20 m before his parachute opens. After his parachute opens if he continues to move uniformly with the velocity attained due to his freefall, the total time taken by the person to reach the ground is (Acceleration due to gravity = 10 ms$^{-2}$)
A piece of length 3.532 m is cut from a rod of length 43.4 m. The length of the remaining rod in metre is (up to correct significant figures)
The range of weak nuclear force is of the order of
The work done to accelerate an electron from rest so that it can have a de Broglie wavelength of 6600 Å is nearly (Planck's constant = \(6.6 \times 10^{-34}\) Js and mass of electron = \(9 \times 10^{-31}\)kg)
Two long straight parallel wires carry currents of 8 A and 10 A in opposite directions. If the distance of separation between the wires is 9 cm, then the net magnetic field at a point between the two wires, which is at a perpendicular distance of 4 cm from the wire carrying 8 A current is
If the radiation emitted by a perfect radiator has maximum intensity at a wavelength of 2900 Å, the intensity of radiation emitted by it is (Stefan-Boltzmann's constant = \(5.67 \times 10^{-8}\) Wm\(^{-2}\)K\(^{-4}\) and Wein's constant = \(2.9 \times 10^{-3}\) mK)
The temperature of a body shown by a faulty Celsius thermometer is 49 °C and by a correct Fahrenheit thermometer is 122 °F. The correction to be applied to the faulty thermometer is
A 200 g sample of water at 80°C is mixed with 100 g of water at 20°C. Assuming no heat loss to the surroundings, what is the final temperature of the mixture?
In the circuit shown, the charge on the left plate of the 20 µF capacitor is \( -50\,\mu C \). The charge on the right plate of the 12 µF capacitor is:
Four electric charges 2 µC, Q, 4 µC and 12 µC are placed on x-axis at distances x = 0, 1 cm, 2 cm and 4 cm respectively. If the net force acting on the charge at origin is zero, then Q =
In a diffraction experiment, the slit is illuminated by light of wavelength 600 nm. The first minimum of the pattern falls at \( \theta = 30^\circ \). Calculate the width of the slit.
An AC current is represented as: $ i = 5\sqrt{2} + 10 \cos\left(650\pi t + \frac{\pi}{6}\right) \text{ Amp} $ The RMS value of the current is:
A particle of mass \( m \) and charge \( q \) moving with velocity \( \vec{v} = v \hat{i} \) is subjected to a uniform electric field \( \vec{E} = E \hat{j} \). The particle will initially have a tendency to move in a circle of radius:
A current flows through a cylindrical conductor of radius \( R \). The current density at a point in the conductor is \( j = \alpha r \) (along its axis), where \( \alpha \) is a constant and \( r \) is the distance from the axis of the conductor. The current flowing through the portion of the conductor from \( r = 0 \) to \( r = \frac{R}{2} \) is proportional to:
If the maximum and minimum amplitudes of an amplitude modulated wave are 9 V and 3 V respectively, then the modulation index is
For a common emitter transistor amplifier, the voltage across the collector resistance is 2.8 V. If the current amplification factor of the transistor is 70 and the collector resistance is 2 k$\Omega$, then the base current is
If the breakdown voltage of a Zener diode is 7.2 V and the maximum power dissipated is 216 mW, then the maximum current through the Zener diode is
If mass of 5 neutrons is x, mass of 2 protons is y and the mass of the nucleus $_{10}X^{20}$ is z, then the binding energy of the nucleus X is (Speed of light in vacuum is c)
If the half life of an element is 10 minutes, then the time taken (in minutes) for the element to decay from 20% to 80% is
If the potential energy of an electron in an orbit of hydrogen atom is $-6.80$ eV, then the energy required to ionize the atom is
If electrons of mass 'm' and de Broglie wavelength '$\lambda$', incident on a metal plate in an X-ray tube, then the minimum wavelength of X-rays emitted is
(h = Planck's constant and c = Speed of light in vacuum)
For a plane electromagnetic wave travelling in free space along X-axis, the magnetic field at a particular point in space is $\vec{B} = 2.1 \times 10^{-8} \hat{k} \, T$. The magnitude of the electric field at this point is