List of top Physics Questions

An iron rod is placed parallel to magnetic field intensity 2000 A/m. The magnetic flux through rod is \(6\times 10^{-4}\) wb and its cross sectional area is 3 cm\(^2\). The magnetic permeability of the rod in wb/A-m is
A potentiometer wire is 4 m long and potential difference of 3V is maintained between the ends. The e.m.f. of the cell which balances against a length of 100 cm of the poteniometer wire is
A condenser of capacity \(C_1\) is charged to potential \(V_1\) and then disconnected. Uncharged capacitor of capacity \(C_2\) is connected in parallel with \(C_1\). The resultant potential \(V_2\) is
The capacitance of a capacitor becomes \(\frac{7}{6}\) times the original value if dielectric slab of thickness \(t = \frac{2d}{3}\) is introduced between the plates, where 'd' is the distance of separation between the plates. The dielectric constant of the slab is
A sonometer wire is vibrating in third overtone. There are
In a stationary wave, all the particles
Waves having a velocity 10m/s, strike a stationary boat near the sea shore. The distance between two consecutive crests of the waves is 40m. After how many second, the consecutive waves strike the boat?
A charge 'Q' C is placed at the centre of a cube. The electric flux through two opposite faces of the cube is
(\(ε_0\) = permittivity of free space)
In fundamental mode, the time required for the sound wave to reach upto the closed end of a pipe filled with air is \(t\) second. The frequency of vibration of air column is
(\(λ\) = wavelength of the wave)
A musical instrument P produces sound waves of frequency 'n' and amplitude 'A'. Another musical instrument Q produces sound waves of frequency n/4. The waves produced by P and Q have equal energies. The amplitude of waves produced by Q will be
Rate of radiation by a black body is 'R' at temperature 'T'. Another body has same area but emissivity is 0.2 and temperature 3T. Its rate of radiation is
An ideal gas expands adiabatically (\(γ = 1.5\)). To reduce the r.m.s. velocity of the molecules 3 times the gas has to be expanded
A black rectangular surface of area A emits energy E per unit time at \(27^{\circ}\) C. If length and breadth is reduced to \((\frac{1}{4})^{th}\) of initial value and temperature is raised to \(327^{\circ}\) C, then energy emitted per unit time becomes
A spring executes S.H.M. with mass 10 kg attached to it. The force constant of spring is 10 N/m. If at any instant its velocity is 40 cm/s, the displacement at that instant is
(Amplitude of S.H.M. is 0.5 m)
The change in internal energy of the mass of gas, when the volume changes from V to 2V at constant pressure P is (\(γ\) is the ratio of specific heat at constant pressure to that of volume) (\(γ = \frac{C_p}{C_v}\))
A simple pendulum oscillates with an angular amplitude \(θ\). If the maximum tension in the string is twice the minimum tension then \(θ\) is
A celsius and a Fahrenheit thermometer are dipped in boiling water. The temperature of water is lowered until the Farenheit thermometer shows \(140^{\circ}\). What is the fall in temperature on the Celsius thermometer?
The work done in splitting a water drop of radius 'R' into 64 droplets is (T is the surface tension of water)
Two small drops of liquid of same radius coalesce to form a big drop. The ratio of the total surface energies after and before the change is
Three liquids have same surface tension and have densities \(ρ_1,ρ_2\) and \(ρ_3\) \((ρ_1 > ρ_2 > ρ_3)\). In three identical capillaries rise of liquid is same. The corresponding angles of contact \(θ_1,θ_2\) and \(θ_3\) are related as
A disc of radius 0.4 m and mass 1 kg rotates about an axis passing through its centre and perpendicular to its plane. The angular acceleration is 10 rad/s\(^2\). The tangential force applied to the rim of the disc is
A body is projected vertically from earth's surface of radius R with velocity equal to half the escape velocity. The maximum height reached by the body is
A stationary body explodes into two parts of masses \(M_1\) and \(M_2\). They move in opposite directions with velocities \(V_1\) and \(V_2\). The ratio of their kinetic energies is
The relative angular speed of hour hand and minute hand of clock is
According to Boyle's law, the product PV remains constant. The SI unit of PV is same as that of