List of top Physics Questions

$A$ $2 \,m$ long solenoid with diameter $2\, cm$ and $2000$ turns has a secondary coil of $1000$ turns wound closely near its midpoint. The mutual inductance between the two coils is

Consider the situation shown in the figure. The wall is smooth but the surfaces of blocks $A$ and $B$ in contact are rough. The friction on $A$ due to $B$ in equilibrium

A stone is thrown at $25 \, \text{m} / \text{s}$ at $53^{o}$ above the horizontal. At what time its velocity is at $45^{o}$ below the horizontal?

The electromagnetic waves travel in free space with the velocity of

The displacement time graph of a moving particle is shown below The instantaneous velocity of the particle is negative at the point

A table fan, rotating at a speed of $2400 \, \, \text{r} \text{p} \text{m}$ is switched off and the resulting variation of the rpm with time is shown in the figure. The total number of revolutions of the fan before it comes to rest is

A ball rolls off the top of stair-way with a horizontal velocity of magnitude $1.8 \, m \, s^{- 1}.$ The steps are $0.20 \, \, \text{m}$ high and $0.20 \, \, \text{m}$ wide. Which step will the ball hit first?

A $2 \, \, \text{kg }$ stone tied at the end of a string $1 m$ long is whirled along a vertical circle at a constant speed of $4 \, m \, s^{- 1}$ . The tension in the string has a value of $52 N$ when the stone is

The dimensional formula for the modulus of elasticity is same as that for:

Which of the modulus of elasticity is involved in compressing a rod to decrease its length ?

Amorphous solids exhibit the property of:

Stress has the dimensions same as that of :

Young's modulus of a body:

If the diameter of the wire is doubled and its length is halved then its Young's modulus (Y)

The potential energy $U$ of two atoms of a diatomic molecule as a function of distance $r$ between the atoms are shown in the given figure.

Read the following statements carefully. 1. The equilibrium separation distance between the atoms is equal to $r_{2}$. 2. At $r=r_{1}$, the force between the atom is repulsive. 3. For $r>r_{2}$, the force between the atoms is attractive. Which of the above statements is true?

The metal cube of side $10\, cm$ is subjected to a shearing stress of $10^{4}N$ $m^{-2}$. The modulus of rigidity if the top of the cube is displaced by $0.05 \,cm$ with respect to its bottom is

For an ideal liquid

An alpha nucleus of energy $\frac{1}{2}mv^{2}$ bombards on a heavy nuclear target of the charge $\textit{Ze}$ . Then the distance of closest approach for the alpha nucleus will be proportional to

The kinetic energy of an electron having de-Broglie wavelength $\lambda $ is ( $h=$ Planck's constant, $m=$ mass of electron)

The $K_{\alpha }$ line obtained for molybdenum $\left(\right.Z=42\left.\right)$ is $0.71 \, \overset{^\circ }{A}$ . Then, the wavelength of the $K_{\alpha }$ line of copper $\left(\right.Z=29\left.\right)$ is

For sodium light, the two yellow lines occur at $\lambda _{1}$ and $\lambda _{2}$ wavelengths. If the mean of these two is $6000 \, \overset{^\circ }{A}$ and $\left|\lambda _{2} - \lambda _{1}\right|=6 \, \overset{^\circ }{A}$ , then the approximate energy difference between the two levels corresponding to $\lambda _{1}$ and $\lambda _{2}$ is

If proton and a - particle are accelerated by the same potential $V$ . Then, the ratio of their wavelengths $\lambda _{\text{P}}:\lambda _{\alpha }$ would be

The energy (in $eV$ ) required to excite an electron from $n=2$ to $n=4$ state in hydrogen atom is

Two radioactive substances $A$ and $B$ have decay constants $5\lambda $ and $\lambda $ respectively. At $ \, t=0$ , a sample has the same number of the two nuclei. The time taken for the ratio of the number of nuclei to become $\left(\frac{1}{e}\right)^{2}$ will be

An $H$ -atom moving with speed $v$ makes a head-on collision with another $H$ -atom at rest. Both the atoms are in the ground state. The minimum value of velocity $v$ for which one of the atoms may excite is