List of top Physics Questions

A body travelling along a straight line traverse one-third the distance with a velocity of $ 5 \,m/s $ . The remaining part of the distance was covered with velocity $ 3 \,m/s $ for half the time and with velocity $ 2 \,m/s $ for the other half of the time. The average velocity of the body over the whole time of motion will be
A ball of mass (m) 0.5 kg is attached to the end of a string having length (l) 0.5 m. The ball is rotated on a horizontal circular path about vertical axis. The maximum tension that the string can bear is 324 N. The maximum possible value of angular velocity of ball (in rad/s) is
A thin ring of mass 2 kg and radius 0.5 m is rolling without slipping on a horizontal plane with velocity 1 m/s. A small ball of mass 0.1 kg, moving with velocity 20 m/s in the opposite direction, hits the ring at a height of 0.75 m and goes vertically up with velocity 10 m/s. Immediately after the collision
A police car with a siren of frequency $8\, kHz$ is moving with uniform velocity $36\, km/hr$ towards a tall building which reflects the sound waves. The speed of sound in air is $320 \,m/s$. The frequency of the siren heard by the car driver is
5.6 L of helium gas at STP is adiabatically compressed to 0.7 L. Taking the initial temperature to be $T_1$, the work done in the process is
A ball of mass 0.2 kg rests on a vertical post of height 5 m. A bullet of mass 0.01 kg, travelling with a velocity v m/s in a horizontal direction, hits the centre of the ball. After the collision, the ball and bullet travel independently. The ball hits the ground at a distance of 20 m and the bullet at a distanceof 100 m from the foot of the post The initial velocity v of the bullet is
A satellite is moving with a constant speed $v$ in a circular orbit about the earth. An object of mass '$m$' is ejected from the satellite such that it just escapes from the gravitational pull of the earth. At the time of its ejection, the kinetic energy of the object is :
A microscope is focussed on an ink mark on the top of a table. lf we place a glass slab of 3 cm thick on it, how should the microscope be moved to focus the ink spot again? The refractive index of glass is 1.5
A $100$ turn closely wound circular coil of radius $ 10\,cm $ carries a current of $ 3.2\,A $ . The magnetic moment of the coil is, approximately
The wavelength of spectral line coming from a distant star shifts from $600\, nm$ to $600.1\, nm$. The velocity of the star relative to earth is
For base station to mobile communication, the required frequency band is
Resultant of two vectors $\vec{A}$ and $\vec{B}$ is of magnitude $P$. If $\vec{B}$ is reversed, then resultant is of magnitude $Q$. What is the value of $P^2 + Q^2$ ?
What is the refractive index of material of a plano convex lens, if the radius of curvature of the convex surface is $10 \,cm$ and focal length of the lens is $30 \,cm$?
An electron having momentum $2.4 \times 10^{-23} \,kg \,ms ^{-1}$ enters a region of uniform magnetic field of $0.15 \,T$. The field vector makes an angle of $30^{\circ}$ with the initial velocity vector of the electron. The radius of the helical path of the electron in the field shall be
When you make ice cubes, the entropy of water
When a ceiling fan is switched on, it makes 10 revolutions in the first 3 seconds. Assuming a uniform angular acceleration, how many rotations it will make in the next 3 seconds?
If the wavelength of 1st line of Balmer series of hydrogen is 6561 ?, the wavelength of the 2 line of series will be
An atom bomb is based on the principle of
Which of the following circular rods, (given radius $r$ and length $l$) each made of the same material and whose ends are maintained at the same temperature will conduct most heat?
A stone of mass 0.3 kg attached to a 1.5 m long string is whirled around in a horizontal circle at a speed of 6 ms. The tension in the string is
A sound absorber attenuates the sound level by 20 dB. The intensity decreases by a factor of
A projectile is thrown in the upward direction making an angle of 60$^{\circ}$ with the horizontal direction with a velocity of 147 $ms^{ - 1}$ Then the time after which its inclination with the horizontal is 45$^{\circ}$, is
A ray is incident on a plane surface. If $\hat{i} + \hat{j} - \hat{k}$ represents a vector along the direction of incident ray.$\hat{i} + \hat{j} $ is a vector along normal on incident point in the plane of incident and reflected ray, then vector along the direction of reflected ray is
A circuit is made up of a resistance $1\, \Omega$ and inductance $0.01\, H$. An alternating emf of $200\, V$ at $50\,Hz$ is connected, then the phase difference between the current and the emf in the circuit is
A motor cycle is going on an overbridge of radius $R$. The driver maintains a constant speed. As the motor cycle is ascending on the overbridge, the normal force on it