List of top Physics Questions

Two electric bulbs are connected one by one across potential difference V. At that time power consumed in them are $P_1 \, and \, P_2 $ respectively. Now, if potential difference V is applied across series combination of these bulbs, what will be total power consumed ?
The internal resistance of a cell of emf 4 V is $ 0.1 \Omega $ It is connected to a resistance of $ 3.9 \Omega $. The voltage across the cell will be
The ratio of cross-sectional areas of two conducting wires made up of same material and having same length is 1 : 2. What will be the ratio of heat produced per second in the wires, when same current is flowing in them?
Colours in thin films are due to
A rocket of mass $100 \,kg$ burns $0.1\, kg$ of fuel per sec. If velocity of exhaust gas is $1 \,km/s^{-1}$, then it lifts with an acceleration of
A beaker of radius $15\, cm$ is filled with a liquid of surface tension $0.75\, N/m$. Force across an imaginary diameter on the surface of the liquid is
Force required to move a mass of $1 \,kg$ at rest on a horizontal rough plane ( $ \mu =0.1 $ and $ g=9.8\,m{{s}^{2}} $ ) is
A shell of mass $10\, kg$ is moving with a velocity of $ 10\,ms^{-1}$ when it blasts and forms two parts of mass $9 \,kg$ and $1 \,kg$ respectively. If the $1^{st}$ mass is stationary, the velocity of the $ 2^{nd} $ is
A particle shows distance - time curve as given in this figure. The maximum instantaneous velocity of the particle is around the point
An electric kettle takes 4 A current at 220 V. How much time will it take to boil 1 kg of water from temperature $20^\circ C ?$ The temperature of boiling water is $100^\circ C $
A current of 3 amp. flows through the $2\, \Omega$ resistor shown in the circuit. The power dissipated in the $5\, \Omega$ resistor is
In gamma ray emission from a nucleus
A simple pendulum is suspended from the ceiling of a lift. When the lift is at rest its time period is $T$. With what acceleration should the lift be accelerated upwards in order to reduce its period to $T/2$ ? (g is acceleration due to gravity).
The magnetic field at the centre of a circular current carrying conductor of radius $r$ is $B_c$. The magnetic field on its axis at a distance $r$ from the centre is $B_a$. The value of $B_c : B_a$ will be
The equivalent resistance between the points $A$ and $B$ will be (each resistance is 15 $\Omega$)
The masses of two radioactive substances are same and their half lives are $1$ year and $2$ years respectively. The ratio of their activities after 6 years will be
A small conducting sphere of radius $r$ is lying concentrically inside a bigger hollow conducting sphere of radius $R$. The bigger and smaller spheres are charged with $Q$ and $q (Q > q)$ and are insulated from each other. The potential difference between the spheres will be
A ray of light enters from a rarer to a denser medium. The angle of incidence is $i$. Then the reflected and refracted rays are mutually perpendicular to each other. The critical angle for the pair of media is
$_{92}U^{235}$ undergoes successive disintegrations with the end product of $_{82}Pb^{203}$.The number of $\alpha$ and $\beta$ particles emitted are
A body of mass $4\, kg$ is accelerated upon by a constant force, travels a distance of $5\,m$ in the first second and a distance of $2\,m$ in the third second. The force acting on the body is
A mass of $10\,kg$ is suspended from a spring balance. It is pulled aside by a horizontal string so that it makes an angle of $60^\circ$ with the vertical. The new reading of the balance is
Two identical metal spheres charged with $+12 \mu F$ and $-8 \mu F$ are kept at certain distance in air. They are brought into contact and then kept at the same distance. The ratio of the magnitudes of electrostatic forces between them before and after contact is
Figure shows a mixture of blue, green and red coloured rays incident normally on a right angled prism. The critical angles of the material of the prism for red, green and blue are $46^\circ$, $44^\circ$ and $43^\circ$ respectively. The arrangement will separate
A body of mass $3 \,kg$ is under a constant force which causes a displacement s in metre in it, given by the relation $s=\frac{1}{3}t^2$, where $t$ is in second. Work done by the force in $2 s$ is
A player caught a cricket ball of mass 150 g moving at a rate of 20 m/s. If the catching process is completed in 0.1s, the force of the blow exerted by the ball on the hand of the player is equal to :