List of top Physics Questions

The magnetic flux through a loop of resistance 10 $\Omega$ varying according to the relation $\phi=6t^{2}+7t+1$, where $\phi$ is in milliweber, time is in second at time t=1 s the induced e.m.f. is
A thin rod of length 'L' is bent in the form of a circle. Its mass is 'M'. What force will act on mass 'm' placed at the centre of this circle? (G = constant of gravitation)
The ratio of wavelengths for transition of electrons from 2nd orbit to $1^{st}$ orbit of Helium $(He^{+})$ and Lithium $(Li^{++})$ is (Atomic number of Helium = 2, Atomic number of Lithium = 3)
A rubber ball filled with water, having a small hole is used as the bob of a simple pendulum. The time period of such a pendulum
In potentiometer experiment, the balancing length is $8 \text{ m}$ when two cells $E_{1}$ and $E_{2}$ are joined in series. When two cells are connected in opposition the balancing length is $4 \text{ m}$. The ratio of the e.m.f. of the two cells $\left( \frac{E_{1{E_{2 \right)$ is
The pressure and density of a diatomic gas ($\gamma = \frac{7}{5}$) changes adiabatically from $(P, \rho)$ to $(P', \rho')$. If $\frac{\rho'}{\rho} = 32$ then $\frac{P'}{P}$ should be
If $E_{a}$ and $E_{q}$ represent the electric field intensity due to a short dipole at a point on its axial line and on the equatorial line at the same distance '$r$' from the centre of the dipole, then}
A coil having an inductance of $\frac{1}{\pi} \text{ H}$ is connected in series with a resistance of $300 \Omega$. If $20 \text{ V}$ from a $200 \text{ Hz}$ source are impressed across the combination, the value of the phase angle between the voltage and the current is
What will be the phase difference between virtual voltage and virtual current when current in the circuit is wattless?
An ideal refrigerator has freezer at a temperature of $-13^{\circ}\text{C}$. The coefficient of performance of the engine is $5$. The temperature of the air (to which heat is rejected) is
Two wavelengths of sodium light $590 \text{ nm}$ and $596 \text{ nm}$ are used one after another to study diffraction due to single slit of aperture $2 \times 10^{-6} \text{ m}$. The distance between the slit and the screen is $1.5 \text{ m}$. The separation between the positions of first maximum of the diffraction pattern obtained in the two cases is
A mass '$M$' is moving with constant velocity parallel to X-axis. Its angular momentum with respect to the origin is
A body (mass $m$) starts its motion from rest from a point distant $R_0$ ($R_0>R$) from the centre of the earth. The velocity acquired by the body when it reaches the surface of earth will be ($G =$ universal constant of gravitation, $M =$ mass of earth, $R =$ radius of earth)}
A block of mass '$M$' rests on a piston executing S.H.M. of period one second. The amplitude of oscillations, so that the mass is separated from the piston, is (acceleration due to gravity, $g = 10 \text{ ms}^{-2}, \pi^2 = 10$ )}
Two spherical soap bubbles of radii '$a$' and '$b$' in vacuum coalesce under isothermal conditions. The resulting bubble has a radius equal to}
The temperature of a gas is measure of}
A machine gun fires bullets of mass $30\text{ g}$ with velocity of $1000\text{ m/s}$. The man holding the gun can exert a maximum force of $300\text{ N}$ on it. How many bullets can he fire per second at most?
A wire $PQ$ has length $4.8\text{ m}$ and mass $0.06\text{ kg}$. Another wire $QR$ has length $2.56\text{ m}$ and mass $0.2\text{ kg}$. Both wires have same radii and are joined as a single wire. This wire is under tension of $80\text{ N}$. A wave pulse of amplitude $3.5\text{ cm}$ is sent along the wire $PQ$ from end $P$. The time taken by the wave pulse to travel along the wire from point $P$ to $R$ is?
A sonometer wire 49 cm long is in unison with a tuning fork of frequency '$n$'. If the length of the wire is decreased by 1 cm and it is vibrated with the same tuning fork, 6 beats are heard per second. The value of '$n$' is
A solid cylinder and a solid sphere having same mass and same radius roll down on the same inclined plane. The ratio of the acceleration of the cylinder '$a_c$' to that of sphere '$a_s$' is
When a monochromatic ray of light is passed through an equilateral glass prism, it is found that the refracted ray in glass is parallel to the base of the prism. If '$i$' and '$e$' denote the angles of incidence and emergence respectively, then}
An alternating voltage $E = 200\sqrt{2} \sin(100t)$ volt is connected to a $1 \mu\text{F}$ capacitor through an a.c. ammeter. The reading of the ammeter shall}
When moving coil galvanometer (MCG) is converted into a voltmeter, the series resistance is '$n$' times the resistance of galvanometer. How many times that of MCG the voltmeter is now capable of measuring voltage?
The self induction ($L$) produced by solenoid of length '$l$' having '$N$' number of turns and cross sectional area '$A$' is given by the formula ($\phi = \text{magnetic flux through one turn}, \mu_0 = \text{permeability of vacuum}$)}
Figure shows two semicircular loops of radii $R_1$ and $R_2$ carrying current $I$. The magnetic field at the common centre '$O$' is