List of top Physics Questions

A nuclear transformation is denoted by $X\left(n, \alpha\right) \,^{7}_{3}Li.$ Which of the following is the nucleus of element $X$ ?

Limit of resolution of a telescope is $4.88 \times 10^{-6}$ rad for light of wavelength 560 nm. Diameter of the objective is

Two coherent monochromatic; light beams of intensities $I$ and $4I$ are superposed. Intensities at constructive and? destructive interferenc positions will be

An ideal gas is taken from point $ A $ to the point $ B $ , as shown in the $ p-V $ diagram, keeping the temperature constant. The work done in the process is :

A Carnot engine whose low temperature reservoir is at $ 7^??, C $ has an efficiency of $ 50\% $ . It is desired to increase the efficiency to $ 70\% $ . By how many degrees should the temperature of the high temperature reservoir be increased ?

A moving coil galvanometer has a resistance of $ 10\, O $ and full scale deflection of $ 0.01\, A $ . It can be converted into voltmeter of $ 10\, V $ full scale by connecting into resistance of :

In Young?? double slit experiment, the slits are $ 3 \,mm $ apart. The wavelength of light used is $ 5000\, ??$ and the distance between the slits and the screen is $ 90 \,cm $ . The fringe width in $ mm $ is :

A circular disc of radius $ R $ rolls without slipping along the horizontal surface with constant velocity $ v_0 $ . We consider a point $ A $ on the surface of the disc. Then the acceleration of the point $ A $ is :

Find the dimensions of electric permittivity.

$ 1\,Wb/m^2 $ is equal to :

The number of free electrons per $ 100 \,mm $ of ordinary copper wire is $ 2 ??10^{21} $ . Average drift speed of electrons is $ 0.25\, mm/s $ . The current flowing is :

A person is standing in an elevator. In which situation he finds his weight less?

The radius of sphere is measured to be $ (2.1\,\pm \,0.5)\,cm. $ Calculate its surface area with error limits:

A block of mass $m$ initially at rest is dropped from a height $h$ on to a spring of force constant $k$. The maximum compression in the spring is $x$ then:

If linear density of a rod of length 3 m varies as $ \lambda =2+x, $ then the position of the centre of gravity of the rod is:

The dimensional formula for the gravitational constant is:

A particle is moving in a circle of radius R with constant speed v. If radius is doubled, then its centripetal force to keep the same speed gets:

When earth moves round the sun, the quantity which remains constant is:

A particle moves along Y-axis in such a way that its y-coordinate varies with time $t$ according to the relation $y = 3 +5t + 7t ^2$. The initial velocity and acceleration of the particle are respectively

$1$ kg body explodes into three fragments. The ratio of their masses is $1:1:3$. The fragments of same mass move perpendicular to each other with speeds $30$ m/s, while the heavier part remains in the initial direction. The speed of heavier part is:

Two rods of same material have same length and area. The heat $ \Delta Q $ flows through them for $12\, min$ when they are joint side by side. If now both the rods are joined in parallel, then the same amount of heat $ \Delta Q $ will flow in:

A machine which is 75% efficient, uses 12 J of energy in lifting 1 kg mass through a certain distance. The mass is then allowed to fall through the same distance. The velocity at the end of its fall is

When a man increases his speed by $2\, ms^{-1}$, the finds that his kinetic energy is doubled, the original speed of the man is

What is the drift velocity of electons, if the current flowing through a copper wire of $1\,mm$ diameter is $1.1\, A$ ? Assume that each atom of copper contributes on electron (Given, density of $Cu= 9 g \, cm^{-3}$ and atomic weight of $Cu = 63$)

Magnification of a compound microscope is $30$. Focal length of eyepiece is $5\, cm$ and the image is formed at a distance of distinct vision $25\, cm$. The magnification of the objective lens is :