List of top Physics Questions

Due to the presence of an em-wave whose electric component is given by \( E = 100 \sin(\omega t - kx) \, \text{N/C} \), a cylinder of length 200 cm holds a certain amount of em-energy inside it. If another cylinder of the same length but half the diameter of the previous one holds the same amount of em-energy, the magnitude of the electric field of the corresponding em-wave should be modified as:

A bead of mass \( m \) slides without friction on the wall of a vertical circular hoop of radius \( R \) as shown in figure. The bead moves under the combined action of gravity and a massless spring \( k \) attached to the bottom of the hoop. The equilibrium length of the spring is \( R \). If the bead is released from the top of the hoop with (negligible) zero initial speed, the velocity of the bead, when the length of spring becomes \( R \), would be (spring constant is \( k \), \( g \) is acceleration due to gravity): 

For a particular ideal gas, which of the following graphs represents the variation of mean squared velocity of the gas molecules with temperature?

A particle of mass \( m \) and charge \( q \) is fastened to one end \( A \) of a massless string having equilibrium length \( l \), whose other end is fixed at point \( O \). The whole system is placed on a frictionless horizontal plane and is initially at rest. If a uniform electric field is switched on along the direction as shown in the figure, then the speed of the particle when it crosses the x-axis is:

If the acceleration due to gravity on the surface of Earth is \( g \), then the acceleration due to gravity on a planet whose diameter is \( \frac{1}{3} \) of that of Earth and same mass as that of Earth is \( g' = ng \), where \( n \) is
A solid sphere rolls without slipping on a horizontal plane. What is the ratio of translational kinetic energy to the rotational kinetic energy of the sphere?
A solid sphere and hollow sphere roll down purely equal distances on the same inclined plane (starting from rest) in time \( t_1 \) and \( t_2 \). Then
The temperature in a city is measured to be 30°C. What is the corresponding temperature in Fahrenheit?
In Young's Double Slit Experiment, monochromatic light of wavelength \( \lambda \) is used. The slits are separated by a distance \( d \), and the screen is placed at a distance \( D \) from the slits. If the fringe width is observed to be \( \beta \), and the distance between the slits and the screen is doubled, what will be the new fringe width?
Find the wavelength in (nm) of incident radiation where the work function is 4.12 eV and the stopping potential is 4V. Given that \( h \nu = 1242 \, \text{eV} \cdot \text{nm} \).
Two charges +7 mC and -4 mC at coordinates (-7, 0, 0) and (7, 0, 0), respectively, find the electrostatic potential energy. \[ \epsilon_0 = 8.85 \times 10^{-12} \, \text{C}^2 \, \text{N}^{-1} \, \text{m}^{-2}. \]
The value of \( E_0 \) is 9.3 V/m and \( c \) is \( 3 \times 10^8 \, \text{m/s} \). Find the value of \( B_0 \).
Find the charge on the capacitor in the steady state. \vspace{1cm} \includegraphics[width=0.7\textwidth]{a.png}
If the angle of prism equals the angle of minimum deviation, and given that the refractive index \( \mu = \sqrt{3} \), then the angle of the prism is:
A proton is moving with a uniform velocity of \( 2 \times 10^8 \, \text{m/s} \) in uniform magnetic and electric fields which are perpendicular to each other. If the electric field is switched off, then the proton moves in a circular path of radius \( 1.6 \times 10^{-5} \, \text{m} \). Then the magnetic field \( B \) is:
Electric flux \( \varphi \) is related with linear charge density \( \lambda \) and surface charge density \( \sigma \) as \( \varphi = \alpha \lambda + \beta \sigma \). Where \( \alpha \) and \( \beta \) are of appropriate dimension. The dimension of \( \frac{\beta}{\alpha} \) is:
Statement 1: Hotter water moves faster than cold water.
Statement 2: Soap water has a higher surface tension than fresh water.
If angles of projection for two projectiles are 30° and 60° then the ratio of velocities at maximum height is:
In a bag, there are 6 white balls and 4 black balls. Two balls are drawn at random. What is the probability that both balls are white?
A solid sphere of mass \( M \), radius \( R \) exerts a gravitational force \( F \) on a point mass. Now a concentric spherical mass \( \frac{M}{7} \) is removed. What is the new force?
Find the current in the circuit at steady state, given \( R = 2 \, \Omega \).
An equiconvex lens of focal length \( f \) is cut into four parts as shown in the diagram. The focal length of each part is
A force \( \mathbf{F} = \hat{i} + 2\hat{j} + 2\hat{k} \) acts on a particle at position vector \( \mathbf{r} = 2\hat{i} + 3\hat{j} + 4\hat{k} \). Find the torque \( \tau \).
Two parallel wires carry currents of 5 A and 4 A in opposite directions. The wires are separated by a distance of 4 cm. Find the net magnetic field at a point midway between the two wires.
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.