List of top Physics Questions

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:

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 :

Hailstone at $0^{\circ}C $ falls from a height of $1\, km$ on an insulating surface converting whole of its kinetic energy into heat. What part of it will melt? $ (g=10\,m/s^{2})$ (Latent heat of ice $ =3.34\times 10^{5}J/kg$)

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:

Calculate the amount of heat (in calories) required to convert $5\, g$ of ice at $0^{\circ}C$ to steam at $100^{\circ}C$ .

A ray falls on a prism $ABC.(AB = BC)$ and travels as shown in figure. The least value of refractive index of material of the prism, should be:

A body takes time $t$ to reach the bottom of an inclined plane of angle $ \theta $ with the horizontal. If the plane is made rough, time taken now is $2t$. The coefficient of friction of the rough surface is:

A body of mass $m$ is moving towards east and another body of equal mass is moving towards north. If after collision both stick together, their speed after collision would be:

A body of mass $1\, kg$ is moving in a vertical circular path of radius $1\, m$. The difference between the kinetic energies at its highest and lowest position is :

In order to obtain time constant of $10\, s$ in an $R-C$ circuit containing a resistance of $10^3 \Omega$ , the capacity of the condenser should be

Two bodies are thrown up at angles of $40^{\circ}$ and $60^{\circ}$ respectively, with the horizontal. If both bodies attain same vertical height, then ratio of velocities with which these are thrown is

A flat mirror revolves at a constant angular velocity making $2\, rev\, s^{-1}.$ With what velocity will a light spot move along a spherical screen with a radius of $10\, m$, if the mirror is at a centre of curvature of the screen ?

A $1\,m$ long steel wire of cross-sectional area $ 1\,mm^{2}$ is extended by $1\, mm$. If $ Y=2\times 10^{11}N/m^{2}$ , then the work done is :

The distance between the sun and the earth be $r$, then the angular momentum of the earth around the sun is proportional to

In which of the following process, convection does not take place primarily?

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

In an equilateral triangle $ABC$, $ F_{1},F_{2} $ and $ F_{3} $ are three forces acting along the sides $AB, BC$ and $AC$ as shown in the given figure. What should be the magnitude of $F_3$, so that the total torque about $ O $ is zero ?

The torque of force $\vec{ F }=(2 \hat{ i }-3 \hat{ j }+4 \hat{ k }) N$ acting at a point $\vec{ r }=(3 \hat{ i }+2 \hat{ j }+3 \hat{ k }) m$ about origin is

$300\, J$ of work is done in sliding a $2 \,kg$ block up an inclined plane of height $10 \,m$. The work done against friction is ( Take $g=10\, m / s ^{2}$ )

We wish to see inside an atom. Assuming the atom to have a diameter of $100 \,pm$, this means that one must be able to resolve a width of say $10\, pm$. If an electron microscope is used, the minimum electron energy required is about