List of top Physics Questions

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 :
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 :
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 :
If percentage change in current through resistor is $1\%$, then the change in power through it would be :
Escape velocity from a planet is $ V_{e}$ . If its mass is increased to $8$ times and its radius is increased to $2$ times, then the new escape velocity would be:
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 $Cu = 63$)
Two plates (area = $S$) charged to $ +q_{1}$ and $ +q_{2}(q_{2} < q_{1})$ brought closer to form a capacitor of capacitance $C$. The potential difference across the plates is: