List of top Physics Questions

A string of length 0.4 m and mass $10^{-2} kg$ is tightly clamped at its ends. The tensior in the string is 1.6 N. Identical wave pulses are produced at one end at equal intervals of time $\Delta t.$ The minimum value of $\Delta t.$ which allows constructive interference between successive pulses, is
A black body is at a temperature of 2880 K. The energy of radiation emitted by this body with wavelength between 499 nm and 500 nm is$U_1$, between 999 nm and 1000 nm is $U_2$ and between 1499 nm and 1500 nm is $U_3$. The Wien constant, b = 2.88 $\times 10^6$ nm-K. Then,
The torque $\tau$ on a body about a given point is found to be equal to A x L, where A is a constant vector and L is the angular momentum of the body about that point. From this it follows that
The linear momentum p of a body varies with time and it is given by equation $ p=x+y{{t}^{2}} $ where $ x $ and $ y $ are constants. The net force acting on the body for a one dimensional motion is :
In a p-n-p transistor working as common base amplifier, current gain is 0.96 and emitter current is 7.2 mA. Then base current will be:
The number of degrees of freedom for each atom of a monatomic gas is
The magnifying power of a simple microscope M is given by
A stone of mass 1 kg tied to the end of a string of length 1 m, is whirled in a horizontal circle, with a uniform angular velocity 2 radian/sec. The tension of the string is (N)
A light body A and a heavy body B have equal linear momentum. Then the K.E. of the body A
A mass of $1 \,kg$ is suspended by means of a thread. The system is (i) lifted up with an acceleration of $4.9 \,m$ $s^{-2}$ (ii) lowered with an acceleration of $4.9 \,m$ $s^{-2}$ . The ratio of tension in the first and second case is
A simple harmonic oscillator oscillates with an amplitude A. At what displacement the kinetic energy and potential energies are equal:
One standard atomic mass unit is:
If 11 identical resistances each of resistance r ohm are in parallel, the equivalent resistance of the combination would be:
If z is the atomic number then radius of g first Bohr orbit is proportional to :
The ratio of specific heat at constant volume $ {{C}_{V}} $ for monoatomic gas to that of polyatomic gas i.e. $ {{C}_{V}} $ (monoatomic)/ $ {{C}_{V}} $ (polyatomic) is
The ratio of magnitudes of average velocity to average speed, is
If a car at rest accelerates uniformly to a speed of 144 km/hour in 20 second it covers a distance of
In an a.c. circuit with phase voltage V and current I, the power dissipated is
The period of revolution of planet A around the sun is 8 times that of B. The distance of A from the sun is how many times greater than that of B from the sun?
The primary winding of a transformer has 500 turns whereas its secondary has 5000 turns. The primary is connected to an A.C. supply 20 V, 50 Hz. The secondary will have an output of
Tesla is the unit of
An electromagnetic radiation of frequency n, wavelength $\lambda $, travelling with velocity v in air, enters a glass slab of refractive index \mu . The frequency, wavelength and velocity of light in the glass slab will be respectively
Two parallel wires in free space are 10 cm apart and each carries a current of 10 A in the same direction. The force exerted by one wire on the other, per metre length is
Standing waves are produced in $10\, m$ long stretched string. If the string vibrates in $5$ segments and wave velocity is $20\,m/s$, its frequency is
When hydrogen atom is in its first excited level, its radius, is