HSC Science (General) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions for Physics

In the expression e = –dΦ/dt, the -ve sign signifies ______ 

A magnet is moved towards a coil (i) quickly (ii) slowly, then the induced e.m.f. is ______ 

The magnetic flux through a loop varies according to the relation Φ = 8t² + 6t + 2, Φ is in milliweber and t is in second. What is the magnitude of the induced emf in the loop at t = 2 seconds?  

Determine the motional emf induced in a straight conductor moving in a uniform magnetic field with constant velocity on the basis of Lorentz force.

The angle at which maximum torque is exerted by the external uniform electric field on the electric dipole is ______.

What is mechanical equilibrium?

What is the value of force on a closed circuit in a magnetic field?

An electric dipole consists of two opposite charges each of magnitude 1 μC, separated by 2 cm. The dipole is placed in an external electric field of 10⁵ N/C. Calculate the:

1. maximum torque experienced by the dipole and
2. work done by the external field to turn the dipole through 180°.

A block of mass m, connected to two springs of spring constants k₁ and k₂ as shown, oscillates on a smooth horizontal surface. What is the effective spring constant of the oscillation?

A metal ring has a moment of inertia 2 kg·m² about a transverse axis through its centre. It is melted and recast into a thin uniform disc of the same radius. What will be the disc's moment of inertia about its diameter?

A uniform disc of mass 10 kg and radius 60 cm rotates about an axis perpendicular to its plane and passing through its centre at 1200 rpm. Calculate its rotation kinetic energy. [Take π² = 10]

Draw a phasor diagram showing e and i in the case of a purely inductive circuit. A 40-turn square coil of side 0.2 m is placed in a magnetic field of induction 0.05 T with the plane of the coil perpendicular to the direction of the field. If the magnetic induction is uniformly reduced to zero in 5 milliseconds, find the emf induced in the coil.

State and prove the theorem of the parallel axis about the moment of inertia.

A particle performs linear SHM with amplitude A and frequency n. Its speed midway between an extreme position and equilibrium position is ______.

When a thin hollow sphere rolls without slipping on a flat surface, the fraction of its total energy associated with rotation is ______.

Light of a certain colour has 2500 waves to the millimetre in air. What is its frequency?

Derive an expression for the emf induced in a straight conductor moving in a uniform magnetic field with constant velocity.

Explain in brief the basic construction of a moving-coil table galvanometer whit a neat labelled diagram.

Prove the theorem of perpendicular axes about the moment of inertia.

In a double-slit experiment using monochromatic light, the fringe pattern shifts by a certain distance on the screen when a mica sheet with a refractive index of 1.6 and thickness of 1.964 µm covers one of the slits. The mica sheet is then removed and the slits-to-screen distance is doubled so that the new fringe width is the same as the observed fringe shift with the mica sheet. Calculate the wavelength of the monochromatic light used.