List of top Physics Questions

Two cells, having the same e.m.f. are connected in series through an external resistance R. Cells have internal resistances $r_1$ and $r_2\, (r_1 >\, r_2)$ respectively. When the circuit is closed, the potential difference across the first cell is zero. The value of R is :-
What is SI unit of electric field intensity?
The radioactivity of a sample is x at time $t_1$ and is y at time $t_2$. If the mean life of the specimen is $\tau$, the number of atoms that have disintegrated in the time interval $(t_2 - t_1)$ is
Emission of light stops as the incident light is cut-off in
You are given n resistors, each of resistance r. They are first combined to get minimum possible resistance, then they are connected to get the maximum possible resistance. The ratio between rrurnmum to maximum resistance is
A critical angle for a medium is $60^\circ.$ Then the refractive index of the medium will be
In a transistor amplifier, the two AC current gains $\alpha $ and $ \beta $ are defined as $\alpha=\frac{\partial I_C}{\partial I_E} $ and $ \beta =\frac{\partial I_C}{\partial I_B}$ the relation between $\alpha$ and $\beta$ is
If the magnetic flux is represented in weber, then the unit of magnetic induction will be
If the electric current in a lamp decreases by $5 \%,$ then the power output decreases by
The electric potential at the surface of an atomic nucleus (Z = 50) of radius $ 9 \times 10^{ - 15} \, m$ is
Two capacitors of capacitance $C_1$ and $C_2$, are connected in parallel. If a charge Q is given to the combination, the charge gets shared. The ratio of the charge on the capacitor $C_1$ to the charge on the capacitor $C_2$ is
As electric dipole placed in a non-uniform electric field in such a way that angle between $p$ and $E$ is not $0^\circ$ or $ 180^\circ $, so it experiences
A block of mass $ 2\,kg $ rests on a horizontal surface. If a horizontal force of $ 5\,N $ is applied on the block the frictional force on, it is $ (\mu _{k}=0.4,\,\mu _{s}=0.5) $
Electromagnetic waves can be deflected by
A bar magnet is held at right angles to a uniform magnetic field. The couple acting on the magnet is to be halved by rotating it from this position. The angle of rotation is
The velocity $v$ of a particle at time $t$ is given by $v=at+\frac{b}{t+c}$ , where $a$, $b$ and $c$ are constants. The dimensions of $a$, $b$ and $c$ are, respectively,
A rectangular vessel when full of water, takes $10$ minutes to be emptied through an orifice in its bottom. How much time will it take to be emptied when half filled with water ?
A solenoid $1.5\, m$ long and $0.4\, cm$ in diameter possesses $10$ turns per cm length. A current of $5\, A$ flows through it. The magnetic field at the axis inside the solenoid is
An unpolarised beam of intensity $I_0$ is incident on a pair of nicols making an angle of $60^\circ$ with each other. The intensity of light emerging from the pair is
If $\lambda_{1}$ and $\lambda_{2}$ are the wavelengths of the first members of the Lyman and Paschen series respectively, then $\lambda_{1}: \lambda_{2}$ is
Two circular coils 1 and 2 are made from the same wire but the radius of the $1^{st} $ coil is twice that of the $ 2^{nd} $coil. What potential difference in volts should be applied across them so that the magnetic field at their centres is the same-
A rectangular block is 5 cm $\times$ 5 cm $\times$ 10 cm in size. The block is floating in water with 5 cm side vertical. If it floats with 10 cm side vertical, what change will occure in the level of water?
An ice block contains a glass ball. When the ice melts within the water containing vessel, the level of water:
Air is blown through a hole on a closed pipe containing liquid. Then, the pressure will
A body of mass 3 kg is under a constant force which causes a displacement s in meters in it, given by the relation s = (\(\frac{1}{3}\)) t2, where t is in s. Work done by the force in 2 s is :