List of top Physics Questions

The $TV$ signals have a bandwidth of $3.7\, MHz$. The number of $TV$ channels that can be accommodated with a band of $3700 \,GHz$ is

Two boys are standing at ends $A$ and $B$ of a ground where $AB = 200\, m$. The boy at B starts running in a direction perpendicular to $AB$ with a speed of $6\, m \,s^{-1}$? The boy at A starts simultaneously with a velocity of $10 \, m \, s^{-1}$ and catches the other at time t where the time $t$ is

A pump on the ground floor of a building can pump up water to fill the tank of $30\, m^3$ in $15\,min$. If the tank is $40\,m$ above the ground, and the efficiency of the pump is $30\,%$, the power consumed by the pump is $(g = 10 \, m \, s^{-2})$

The increase in the height of the tower of height $200\,m$ to get its coverage range tripled is

Let $E _{1}( r ), E _{2}( r )$ and $E _{3}( r )$ be the respective electric fields at a distance $r$ from a point charge $Q , an$ infinitely long wire with constant linear charge density $\lambda$, and an infinite plane with uniform surface charge density $\sigma$. If $E_{1}\left(r_{0}\right)=E_{2}\left(r_{0}\right)=E_{3}\left(r_{0}\right)$ at a given distance $r_{0}$, then

If the focal length of objective lens is increased then magnifying power of

Two cities are $150\, km$ apart. Electric power is sent from one city to another city through copper wires. The fall of potential per km is $8\, volt$ and the average resistance per km is $0.5\, \Omega$. The power loss in the wire is

Hydrogen atom in ground state is excited by a monochromatic radiation of $\lambda$ = 975 $\mathring{A}$. Number of spectral lines in the resulting spectrum emitted will be

A black hole is an object whose gravitational field is so strong that even light cannot escape from it. To what approximate radius would earth (mass $= 5.98 \times 10^{24} \, kg$) have to be compressed to be a black hole?

Light with an energy flux of $ 25 \times 10^4 W m^{-2} $ falls on a perfectly reflecting surface at normal incidence. If the surface area is $ 15 c m^2 $, the average force exerted on the surface is

A projectile is fired from the surface of the earth with a velocity of $5\, m s^{- 1}$ and angle $\theta$ with the horizontal. Another projectile fired from another planet with a velocity of $3\,ms^{ - 1}$ at the same angle follows a trajectory which is identical with the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the planet is (in $ms^{ - 2}$ ) is (Given $g= 9.8 \,ms^{ - 2}$)

A transformer having efficiency of 90% is working on $200\, V$ and $3 \,kW$ power supply. If the current in the secondary coil is $6\, A$, the voltage across the secondary coil and the current in the primary coil respectively are

A monoatomic gas at a pressure $P$, having a volume $V$ expands isothermally to a volume $2V$ and then adiabatically to a volume $16\,V$. The final pressure of the gas is (Take $\gamma =5/3 )$

The resistances in the two arms of the meter bridge are $5\, \Omega$ and $R\, \Omega$ respectively. When the resistance $R$ is shunted with an equal resistance, the new balance point is at $1.6l_1$. The resistance $R$ is

A conducting sphere of radius $R$ is given a charge $Q$. The electric potential and the electric field at the centre of the sphere respectively are

A particle is moving such that its position coordinates (x, y) are (2 m, 3 m) at time t = 0, (6 m, 7 m) at time t = 2 s and (13 m, 14 m) at time t = 5 s. Average velocity vector $ ( \vec{ v_{av}})$ from t = 0 to t = 5 s is .

When the gas expands with temperature using the relation $ V=KT^{2/3} $ for the temperature change of $ 40\,K, $ the work done is

Which quantity is transmitted with propagation of longitudinal waves through a medium?

Mass number of an atom is the sum of

Which of the following relation is called mirror equation?

Light from a point source in air falls on a spherical glass surface ( $ n=1.67 $ and radius of curvature $ =25\,cm $ ). The distance of the light source from the glass surface is $ 95\,cm $ . At what position, the image is formed?

For transistor the value of $ \beta $ is $50$ then, the value of $\alpha$ is

A car moving on a straight road covers $ 1/3 $ of the distance with $ 25\,km/h $ and rest with $ 75\,km/h $ . The average speed is

To determine the coefficient of friction between a rough surface and a block, the surface is kept inclined at $45^{\circ}$ and the block is released from rest. The block takes a time $t$ in moving a distance $d$. The rough surface is then replaced by a smooth surface and the same experiment is repeated. The block now takes a time $t / 2$ in moving down the same distance $d$. The coefficient of friction is

Three capacitors $3\, \mu F , 6 \, \mu F$ and $6\, \mu F$ are connected in series to a source of $120 \, V$. The potential difference, in volt, across the $3 \, \mu F$ capacitor will be