List of top Physics Questions

In a Carnot engine, if the temperatures of the source and sink are both decreased by 100 K, the efficiency:
Two particles of masses 2 kg and 4 kg are separated by a distance of 3 m. The moment of inertia of the system of the two particles about an axis passing through the centre of mass of the system and perpendicular to the line joining the two particles is
The image formed by a convex mirror of focal length 30 cm is a quarter of the size of the object. The distance of the object from the mirror is

If Young’s modulus of elasticity is $Y = \dfrac{2mg l^2}{5b t e}$, where ‘g’ is the acceleration due to gravity, ‘m’ is the mass, ‘l’ is the length, ‘b’ is the breadth, ‘t’ is the thickness and ‘e’ is the elongation, then the value of $k$ is

Two charges +q and -q, each 1 $\mu$C are arranged as shown in the figure. If x = 2 cm and y = 3 cm then potential difference ($V_A - V_B$) is

A particle of charge \( q \) is shot with speed \( V \) towards another fixed particle of charge \( Q \). It reaches the closest distance \( r \) and then returns. If \( q \) were shot with speed \( 2V \), then the closest distance of approach of \( Q \) is:
A body of mass 2 kg is on an inclined plane of inclination 30° and coefficient of friction is $ \frac{1}{\sqrt{3}} $. The minimum force required to move the body up the inclined plane is: \[ \text{(Acceleration due to gravity = 10 ms}^{-2}\text{)} \] Options:
To generate the high magnetic fields, the synchrotron uses
With respect to air, the critical angle in a medium for red light of wave length $ \lambda_1 $ is $ \theta $. Other facts remaining same, the critical angle for yellow light of wave length $ \lambda_2 $ will be Options:
Flux coming out from a unit positive charge kept in air is
The density of a substance is 4 g/cc. In a system in which the unit of length is 5 cm and the unit of mass is 20 g, the density of the substance is:
The bulk modulus \( B \) and compressibility \( k \) are related by:
Physically, the self-inductance plays the role of:
At any instant \( t \), the vertical distance \( Y \) and horizontal distance \( X \) of a projectile are given by \[ 2Y = 6t - g t^2 \quad \text{and} \quad X = 4t, \] The initial velocity of the projectile is:
The relation between the mean life time \( \tau \) and the half life time \( T_{1/2} \) of a radioactive substance is:

The de Broglie wavelength of the most energetic photoelectrons emitted from a photosensitive metal of work function \( \phi \), when light of frequency \( \nu \) is incident on it, is \( \lambda \). Then find \( \nu \) in terms of Planck’s constant \( h \), mass of electron \( m \), and other constants.  

Which of the following statements regarding the damping force of a damped oscillator is NOT correct? Options:
The radio horizon of the transmission of an antenna placed on the 20\(^\text{th}\) floor in a shopping mall, where the height of each floor is 2 m is
A car is moving with a speed of 5 m/s on a circular road having radius of curvature 10 m and coefficient of friction 0.5. For the safe journey of the car, the banking angle of the road should be:
The distance of closest approach of an alpha particle to a nucleus when the alpha particle moves towards the nucleus with linear momentum P is d. The distance of closest approach of alpha particle to nucleus, if the linear momentum of the alpha particle is 1.5 P
A galvanometer has a deflection of 25 divisions for a current of 0.1 A flowing through it. Then the current sensitivity of the galvanometer is
A disc starts rotating from rest with constant acceleration and attains angular velocity of 20 rad/s in 5 seconds. The total angular displacement during this interval is
The temperature of the surface of Sun is 6000 K. The wavelength corresponding to the maximum energy is nearly (Wien's constant, \( b = 2.89 \times 10^{-3} \, \text{mK} \))
In a photoelectric graph of stopping potential vs frequency, straight line makes angle \( \theta \) with Y-axis. Then \( \tan \theta = \):
The time period of revolution of an electron in an orbit of principal quantum number $ n $ is $ T $. If the relation between time period and principal quantum number is $ T \propto n^3 $, then $ x = $