List of top Physics Questions

A magnetic needle kept in a non-uniform magnetic field experiences:

If power dissipated in the $9~\Omega$ resistor in the circuit shown is 36 W, the potential difference across the $2~\Omega$ resistor is: figure [H]

figure

A moving coil galvanometer has 150 equal divisions. Its current sensitivity is 10 divisions per mA and Voltage sensitivity is 2 divisions per millivolt. In order to read each division 1 volt, the resistance in ohms to be connected in series is:

A wire of length L carrying a current of I ampere is initially bent in the form of a circular coil of one turn. If the same wire is bent into a circular coil of two turns without any change in the current, then the magnetic field at the center of the coil:

For an astronomical telescope of length 126 cm in normal adjustment, if the focal length of the objective is 850 % more than that of its eyepiece, then the focal length of the eyepiece is:

If Young's double slit experiment is done in air first and then if the experiment is conducted by immersing the apparatus in water, the fringe width:

Electric flux through cube of side 'a' enclosing charge 'q' is:

The mass and length of a string are 10 g and 100 cm respectively. If the tension in the string is increased from 400 N to 900 N, then the increase in the frequency of transverse vibration of the string is:

When a light ray incidents on an equilateral prism of material of refractive index $\sqrt{2}$, the angle of minimum deviation is D. If the light ray incidents on another equilateral prism of material of refractive index $\sqrt{3}$, then the angle of minimum deviation is:

If electric potential is constant in a region, electric field in that region is:

If the mean free path of a nitrogen molecule in a vessel containing nitrogen at a pressure of 2.1 atm and a temperature of $27^{\circ}C$ is $\lambda$, then its mean free path at a pressure of 1.65 atm and a temperature of $57^{\circ}C$ is:

Initially a body is at a temperature of $50^{\circ}C$. If the temperature of the body is increased by $54^{\circ}F$, then its final temperature will be:

A Carnot engine having an efficiency of 20 % is used as a refrigerator. If the amount of heat absorbed from the reservoir at low temperature is 200 J, then the work done on the refrigerator is:

During an adiabatic process, if the volume of 4 moles of a monoatomic gas initially at a temperature of $127^{\circ}C$ increases by 7 times, then the work done by the gas is:

A metallic wire of density $\rho$ is placed horizontally on the surface of a liquid with surface tension $T$. What is the maximum radius the wire can have so that it remains supported by surface tension?

A metal ball of emissivity 4/7 and surface area 100 $cm^2$ is at a temperature of $127^{\circ}C$. If the temperature of the surroundings is $27^{\circ}C$, then the rate of loss of heat of the ball is:

The work done in stretching a wire by 1 mm is 2 J. The work necessary for stretching another wire of the same material but triple the radius and one third of length by 1 mm is:

For a body in simple harmonic motion. Potential energy (PE), Kinetic energy (KE), Total energy (TE) are measured as a function of displacement x. Which of the following statements is true?

A particle executes simple harmonic motion with time period 'T' and amplitude 'a'. The magnitude of average velocity of the particle over the time interval during which it travels a distance from extreme position to a/2 is:

A solid sphere and a thin circular ring of same mass and same radii are in rotational motion with same angular speeds about their diameters. Find the ratio of works done to stop them, $W_{sphere} / W_{ring}$:

A thin square shaped copper plate of uniform mass distribution of side 4 m has its centre of mass at (2, 2). If at its top right corner, a square of 2 m side is cut from the plate, the centre of mass of the remaining plate is:

A rocket is fired vertically from the surface of the earth with quarter the escape speed. If R is radius of the earth, the maximum altitude reached by the rocket is:

A 15 W machine used $(3i + 5j + 6k)$ N force for 6 seconds to lift a body through a distance of X m along x - axis. The value of X is:

A man weighing 80 kg is standing on a trolley weighing 320 kg. The trolley is resting on frictionless horizontal rails. If the man starts walking on the trolley with a speed of 1 $ms^{-1}$, then after 4 seconds his displacement relative to the ground will be:

A motor boat covers a given distance in 6 hours moving down stream in a river. It covers the same distance in 10 hours moving upstream. The time it takes to cover the same distance in still water is: