List of top Physics Questions

The unit of electric field intensity is:
In a p-n junction diode, the reverse saturation current doubles for every rise in temperature of:
The work done by a conservative force in a closed path is:
A particle moves with uniform acceleration along a straight line. The average velocity over an interval is equal to the instantaneous velocity at:
A convex lens of focal length 20 cm forms a real image at 30 cm from the lens. The object distance is:
The half-life of a radioactive element is 8 days. The fraction remaining after 32 days is:
A resistor of \(10\,\Omega\) and an inductor of \(0.1\,\text{H}\) are connected in series to a \(100\ \text{V}, 50\ \text{Hz}\) AC source. The impedance of the circuit is:
The escape velocity from the surface of Earth is 11.2 km/s. If the radius of Earth is doubled and mass remains the same, the new escape velocity will be:
The dimensional formula for magnetic flux is:
In Young's double-slit experiment, the fringe width is 0.6 mm. If the distance between the slits and screen is doubled, and the separation between slits is halved, the new fringe width will be:
A body is projected with velocity 20 m/s at an angle of \(30^\circ\) to the horizontal. The maximum height reached by the body is (\(g = 10\ \text{m/s}^2\)):
Two capacitors of capacitance 2 \(\mu\)F and 4 \(\mu\)F are connected in series. The equivalent capacitance is:
The voltage and current of an ac circuit are represented as \( V = 100 \sin(100t) \) volt and \( i = 100 \sin(100t + \frac{\pi}{3}) \) mA respectively. The power dissipated in the circuit is:
Equation of electric field of a plane electromagnetic wave is given as:
\[ E_z = 60 \sin(500x + 1.5 \times 10^{11} t) \, \text{V/m}. \] Write the equation for the magnetic field of the wave.
Calculate the electric field intensity at a point just near the surface of a charged plane sheet, measured from its mid-point. [ \( \sigma = 8.85 \, \mu C/m^2 \) ]
State any four advantages of light emitting diode (LED).
A light ray falls on a rectangular glass slab as shown in the figure. If total internal reflection occurs at the vertical face of the slab at point \( B \), the refractive index of glass is:
A light ray falls on a rectangular glass slab
Two thin convex lenses are kept in contact coaxially. If the focal length of the combination is $4~\text{cm$ and the sum of the focal lengths of the two lenses is $18~\text{cm}$, then the focal length of the lens of low power is}
If two light waves of intensities \( I \) and \( 4I \) superimpose at a point with a phase difference of \( \frac{\pi}{2} \), then the resultant intensity at that point is
Images of same size are formed by a convex lens when an object is placed either at 20 cm or 10 cm distance from the lens. The focal length of the lens is
A solid sphere of mass \( M \) and radius \( R \) is rolling without slipping with speed \( v \). Its total kinetic energy is:
The angular velocity of a circular disc rotating with uniform angular acceleration increases from 20 rad s-1 to 50 rad s-1 in a time of 10 seconds. The number of rotations made by the circular disc during this period is:
The time period of oscillations of a spring of force constant 65 N m-1 with its upper end fixed to a rigid support and carrying a mass of 650 g at its lower end is:
Two bodies of masses $2~\text{kg}$ and $3~\text{kg}$ move at right angles with velocities $20~\text{m/s}$ and $10~\text{m/s}$ respectively.
Then the velocity of the centre of mass of the system is
If the displacement of a particle executing simple harmonic motion is given by \( x = 0.5 \cos(125.6\,t) \), then the time period of oscillation of the particle is nearly (Here \(x\) is displacement in metre and \(t\) is time in second)