List of top Physics Questions

A mass of 100 g is projected with an initial velocity of 12 m/s at an angle of 60° with the horizontal. Find the difference between the kinetic energy at the point of projection and the kinetic energy at the highest point.
A force \( \mathbf{F} = 2\hat{i} + 3\hat{j} + 5\hat{k} \) acts on a particle moving in the direction of \( \mathbf{r} = 2\hat{i} + 3\hat{j} + \beta \hat{k} \). Find the value of \( \beta \) when the work done is zero.
In a sound wave, the displacement of the air particles follows the equation \( y = A \cos(kx - \omega t) \). What is the wave velocity?
What is the time period of a simple pendulum of length \( L \) and acceleration due to gravity \( g \)?
In a resistive circuit, the power dissipated by a resistor \( R \) when a current \( I \) flows through it is given by \( P = I^2 R \). What happens to the power when the current is doubled?
A block of mass \( m \) is moving with velocity \( v \) on a smooth horizontal surface. If a constant force \( F \) is applied to the block, what is the work done by this force after 5 seconds?
In the context of the photoelectric effect, what is the threshold frequency \( f_0 \) for a metal if the work function is \( \phi = 2 \, \text{eV} \)?
Monochromatic light of green color is used in Young’s double slit experiment and an interference pattern is observed on a screen. If the green light is replaced by red monochromatic light of the same intensity, how will the fringe width of the interference pattern be affected? Justify your answer.
Write the conditions under which two light waves originating from two coherent sources can interfere each other (i) constructively, and (ii) destructively, in terms of wavelength. Can these be applied for two lights originating from two sodium lamps? Give reason.
The cut-off voltage \( V_0 \) versus frequency \( \nu \) of the incident light curve is a straight line with a slope of \( \frac{h}{e} \). Explain this observation.
The figure shows the plot of magnitude of induced emf (\( \varepsilon \)) versus the rate of change of current in two coils ‘1’ and ‘2’. Which coil has a greater value of self-inductance and why?
plot of magnitude of induced emf
A square loop MNPK of side \( l \) carrying a current \( I_2 \) is kept close to a long straight wire in the same plane and the wire carries a steady current \( I_1 \) as shown in the figure. Obtain the magnitude of magnetic force exerted by the wire on the loop.
square loop MNPK of side l carrying a current I2
In which cases does a charged particle not experience a force in a magnetic field?
In Bohr’s model of hydrogen atom, find the percentage change in the radius of its orbit when an electron makes a transition from \( n = 3 \) state to \( n = 2 \) state.
In Young's double slit experiment, the screen is moved 30 cm towards the slits. As a consequence, the fringe width of the pattern changes by 0.09 mm. If the slits separation used is 2 mm, calculate the wavelength of light used in the experiment.
In an electromagnetic wave travelling in free space, the amplitude of magnetic field is \( 6.0 \times 10^{-4} \ \text{T} \). The amplitude of its electric field is:
The magnetic flux linked with a closed coil (in Wb) varies with time \( t \) (in s) as \( \phi = 5t^2 + 4t - 2 \). If the resistance of the circuit is 14 \( \Omega \), the magnitude of induced current in the coil at \( t = 1 \) s will be:
Which of the following substances has magnetic permeability less than that of free space?
A particle of mass \( m \) and charge \( q \) moves along the y-axis in a region in which a uniform magnetic field \( \vec{B} \) is pointing along the x-axis. The Lorentz force acting on the charge will point along:
Three wires A, B, and C of the same material have lengths and area of cross-sections as \( (2l, \frac{A}{2}) \), \( (l, A) \) and \( (\frac{l}{2}, 2A) \), respectively. If the resistances of these wires are \( R_A, R_B, R_C \) respectively, then:
Two point charges Q and \( -q \) are held \( r \) distance apart in free space. A uniform electric field \( \vec{E} \) is applied in the region perpendicular to the line joining the two charges. Which one of the following angles will the direction of the net force acting on charge \( -q \) make with the line joining Q and \( -q \)?
A bar magnet is held with its length along the axis of a closed coil. Initially, the south pole of the magnet faces the coil. If the magnet is moved towards the coil, explain how a current is induced in the coil and in what direction.
Find the ratio of minimum to maximum wavelength of radiations emitted when an electron jumps from higher energy state into ground state of hydrogen atom.
In a double slit experiment, the two slits are 1.5 mm apart. The slits are illuminated by a mixture of lights of wavelengths of 600 nm and 400 nm, and the interference pattern is observed on a screen 1.5 m away from the slits. Find the minimum distance of the point from the central maximum at which bright fringes of the interference patterns of the two wavelengths coincide.
A long straight wire is held vertically and carries a steady current in upward direction. The shape of magnetic field lines produced by the current-carrying wire are :