List of top Physics Questions

A transistor has a base current of 1mA and emitter current 90mA. The collector current will be
Which of the following is best nuclear fuel
The back emf induced in a coil, when current changes from 1 ampere to zero in one milli-second, is 4 volts. The self inductance of the coil is
An alternating voltage V=V₀ω t is applied across a circuit. As a result, a current I=I₀(ω t-π/2) flows in it. The power consumed per cycle is
A resistance R and inductance L and a capacitor C are connected in series with an AC supply. The resistance of R is 16Ω, inductive reactance =24Ω and capacitive reactance =12Ω. If the current in the circuit is 5A, find the potential difference across R, L and C.
Two solenoids of same cross-sectional area have their lengths and number of turns in ratio of 1:2. The ratio of self-inductance of two solenoids is
The diameter of the objective of a telescope is a, its magnifying power is m and wavelength of light is λ. The resolving power of the telescope is
Which of the following quantities does not change when a resistor connected to a battery is heated due to the current?
In a region, the potential is represented by V(x,y,z)=6x-8xy-8y+6yz, where V is in volts and x,y,z are in metres. The electric force experienced by a charge of 2 coulomb situated at point (1,1,1) is:
Two metallic spheres of radii 1 cm and 3 cm are given charges of -1×10⁻²C and 5×10⁻²C respectively. If these are connected by a conducting wire, the final charge on the bigger sphere is
A source has wavelength 60 cm when it is stationary. If the speed of sound in air is 320m s⁻¹ and the source moves with speed 20m s⁻¹, the wavelength in the forward direction will be
A charge +q is at a distance L/2 above a square of side L. Then what is the flux linked with the surface?
In the equation PV^γ=constant, the value of γ is unity. Then the process is
A simple pendulum has time period T. Its time period in a lift which is moving upwards with acceleration 3m s⁻² is
A wave y=a(ω t-kx) on a string meets with another wave producing a node at x=0. Then the equation of the unknown wave is
One kilogram of ice at 0C is mixed with one kilogram of water at 80C. The final temperature of the mixture is (Take specific heat of water = 4200J kg⁻¹K⁻¹, Latent heat of ice = 336kJ kg⁻¹)
3 moles of an ideal gas at temperature 27C are mixed with 2 moles of an ideal gas at temperature 227C. Determine the equilibrium temperature of the mixture, assuming no loss of energy.
An ideal refrigerator has a freezer at a temperature of 130C. The coefficient of performance of the engine is 5. The temperature of the air (to which heat is rejected) is
Suppose the gravitational force varies inversely as the nth power of distance. Then the time period of a planet in circular orbit of radius R around the sun will be proportional to
Two planets A and B have the same material density. If the radius of A is twice that of B, then the ratio of the escape velocity vA/vB is
The upper end of a wire of diameter 12 mm and length 1 m is clamped and its other end is twisted through an angle of 30^. The angle of shear is
The ratio of the accelerations for a solid sphere (mass m and radius R) rolling down an incline of angle θ without slipping and slipping down the incline without rolling is
A system consists of three particles each of mass m and located at (1,1), (2,2) and (3,3). The coordinates of the centre of mass are
A spring is compressed between two toy carts of mass m₁ and m₂. When the toys are released, the springs exert equal and opposite average forces for the same time on each cart. If v₁ and v₂ are the velocities of the toy carts and there is no friction between the toy carts and the ground, then:
The potential energy for a force field is given by U(x,y) = (x+y). The force acting on a particle at position given by coordinates (0, π/4) is: