List of top Physics Questions

A magnetic field does not interact with:
The magnitude of the magnetic field due to a circular coil of radius R carrying a current I at its centre is
The radius of the current carrying circular coil is doubled keeping the current passing through it the same. Then the ratio of the magnetic field produced at the centre of the coil before the doubling of the radius to the magnetic field after doubling of the radius is:
The properties of a material required to make permanent magnets are
Find the pole strength of a magnet of length 2 cm, if the magnetic field strength \( B \) at distance 10 cm from the centre of a magnet on the axial line of the magnet is \( 10^{-4} \, \text{T} \).
A charged particle is moving in a uniform magnetic field \( \mathbf{B} = 2\hat{i} + 3\hat{j} \) T. If it has an acceleration of \( \mathbf{a} = \alpha\hat{i} - 4\hat{j} \) m/s², then the value of \( \alpha \) will be:
A conducting loop of radius \( \frac{10}{\sqrt{\pi}} \) cm is placed perpendicular to a uniform magnetic field of 0.5T. The magnetic field is decreased to zero in 0.5 s at a steady rate. The induced emf in the circular loop at 0.25s is:
The free space inside a current carrying toroid is filled with a material of susceptibility \( \chi = 2 \times 10^{-2} \). The percentage increase in the value of magnetic field inside the toroid will be:
For a given pair of transparent media, the critical angle for which colour is maximum?
Pick the correct answer from the following two statements:
(a) Virtual image can be seen with the eyes.
(b) Virtual image can be captured on the screen.
An equiconvex lens made of glass of refractive index \(\frac{3}{2}\) has focal length f in air. It is completely immersed in water of refractive index \(\frac{4}{3}\). The percentage change in the focal length is
When light propagates through a given homogeneous medium, the velocities of
When one light ray is reflected from a plane mirror with 30° angle of reflection, the angle of deviation of the ray after reflection is :
The colour which has the highest critical angle of incidence is
If \( r_1 \) and \( r_2 \) are the angles of refraction at the first face and second face of a prism, then the angle of the prism is:
A convex lens has radius of curvature \( R = 40 \, \text{cm} \) for both surfaces and refractive index \( \mu = 1.5 \). Find the focal length.
The magnifying power of a telescope with tube length 60 cm is 5. Then the focal length of its eye piece is:
A tank is filled with benzene to a height of \(120~\text{mm}\). The apparent depth of a needle lying at the bottom of the tank, as seen through a microscope, is found to be \(80~\text{mm}\). The refractive index of benzene is
Two point charges \(q\) and \(-3q\) are kept 12 cm apart. The distance of the point from \(q\) on the line between two charges at which potential due to this system of charges is zero will be:
An isolated sphere has a capacitance of 60 pF, what is the radius of the sphere?
A dielectric of dielectric constant $ K $ is introduced such that half of its area of a capacitor of capacitance $ C $ is occupied by it. The new capacity is
When $ 10^{19} $ electrons are removed from a neutral metal plate, the electric charge on it is
State and prove the principle of conservation of angular momentum.
A flask contains Hydrogen and Argon in the ratio 2:1 by mass. The temperature of the mixture is 30°C. The ratio of average kinetic energy per molecule of the two gases (K argon/K hydrogen) is:
(Given: Atomic Weight of Ar = 39.9)
Answer the following questions:
What is the value of resistance for an ideal voltmeter?