List of top Physics Questions

Cobalt-$60$ is useful in cancer therapy Cobalt-$60$ is a source of $\gamma$-radiations capable of killing cancerous cells.
A thin stainless steel needle can lay floating on a still water surface. Any object floats when the buoyancy force balances the weight of the object.
Acceleration due to gravity at earth's surface is $g \,ms ^{-2}$. Find the effective value of gravity at a height of $32\, km$ from sea level $:\left(R_{e}=6400 \,km \right)$
Near earths surface, time period of a satellite is $4 h$. Find its time period at height $4R$ from the centre of earth :
A body of mass $0.1\, kg$ attains a velocity of $ 10\,ms^{-1}$ in $0.1 \,s.$ The force acting on the body is :
If force $\vec{ F }= 5 \hat{ i }+3 \hat{ j }+4 \hat{ k }$ makes a displacement of $\vec{ s }=6 \hat{ i }-5 \hat{ k }$, work done by the force is :
A body is moving in a circular path with acceleration $a$. If its velocity gets doubled, find the ratio of acceleration after and before the change :
A ball is thrown from height $h$ and another from $ 2h $ The ratio of time taken by the two balls to reach ground is:
A ball is thrown upwards, it takes $4 s$ to reach back to the ground. Find its initial velocity :
Interference was observed in an interference chamber when air was present. Now, the chamber is evacuated and if the same light is used, a careful observation will show:
$300\, J$ of work is done in sliding a $2 kg$ block up an inclined plane of height $10 \,m$. Taking $g=10\, m / s ^{2}$, work done against friction is :
Aerofils are so designed that the speed of air:
The magnetic moment has dimensions of:
$27$ small drops each having charge $q$ and radius $r$ coalesce to from big drop. How many times charge and capacitance will become?
In refraction, light waves are bent on passing from one medium to the second medium, because, in the second medium:
According to Bernoulli's equation $\frac{P}{\rho g}+h+\frac{1}{2} \frac{v^{2}}{g}=$ constant The terms $A, B$ and $C$ are generally called respectively :
A wire is cut into four pieces, which are put together by sides to obtain one conductor. If the original resistance of wire was $ R $ , the resistance of the bundle will be:
A wire mesh consisting of very small squares is viewed at a distance of $8 \,cm$ through a magnifying converging lens of focal length $10\, cm$, kept close to the eye. The magnification produced by the lens is
A uniform rod of length $\ell$ and mass $m$ is free to rotate in a vertical plane about $A$. The rod initially in horizontal position is released. The initial angular acceleration of the rod is (Moment of inertia of rod about $A$ is $\frac{m \ell^{2}}{3}$ ):
When sound waves travel from air to water, which one of the following remains constant?
If $a_{r}$ and $a_{t}$ represent radial and tangential accelerations, the motion of a particle will be uniformly circular if:
Consider the following equation of Bernoulli's theorem. $P+\frac{1}{2} \rho v^{2}+\rho g h=K \text { (constant) }$ The dimensions of $K / P$ are same as that of which of the following ?
An $L-C$ circuit is in the state of resonance. If $C=0.1\, \mu F$ and $L=0.25\, H$, neglecting ohmic resistance of circuit, what is the frequency of oscillations?
A forward biased diode is :-
Which of the following statements is incorrect?