MAH-MHT CET (PCM/PCB) entrance exam Question Bank Solutions

The magnetic flux through a coil perpendicular to its plane is varying according to the relation Φ = (5t³ + 4t² + 2t - 5) Weber. If the resistant of the coil is 5 ohm, then the induced current through the coil at t = 2 sec will be ______.

Magnetic flux Φ in weber in a closed circuit of resistance 10Ω varies with time Φ (sec) as Φ = 6t² - 5t + 1. The magnitude of induced current at t = 0.25s is ______.

An α -particle of energy 5 Me V is scattered through 180° by a fixed uranium nucleus. The distance of closest approach is of the order of ______.

An ideal transformer converts 220 V a.c. to 3.3 kV a.c. to transmit a power of 4.4 kW. If primary coil has 600 turns, then alternating current in secondary coil is ______.

Two coils P and Q are kept near each other. When no current flows through coil P and current increase in coil Q at the rate 10A/s, the emf in coil P is 15mV. When coil Q carries no current and current of 1. 8A flows through coil P, the magnetic flux linked with the coil Q is ______.

An iron rod is placed parallel to magnetic field of intensity 2000 Am^-1. The magnetic flux through the rod is 6 × 10⁻⁴ Wb and its cross-sectional area is 3 cm². The magnetic permeability of the rod in Wb A^-1m^-1 is ______.

Magnetic flux passing through a coil is initially 4 × 10^-4 Wb. It reduces to 10% of its original value in t second. If the emf induced is 0. 72 mV then t in second is ______.

An iron rod of 0.2 cm² cross-sectional area is subjected to a magnetising field of 1200 Am^-1. If the susceptibility of iron is 599, then the magnetic flux produced is ______.

The damping force of an oscillator is directly proportional to the velocity. The unit of constant of proportionality is ______.

A thin uniform rod has mass M and length L The moment of inertia about an axis perpendicular to it and passing through the point at a distance `"L"/3` from one of its ends, will be ______.

A uniform disc of radius ' a' and mass 'm' is rotating freely with angular speed 'ω' in a horizontal plane, about a smooth fixed vertical axis through its centre. A pa1ticle of mass 'm' is then suddenly attached to the rim of the disc and rotates with it. The new angular speed is ______

A particle starting from rest moves along the circumference of a circle of radius r with angular acceleration a. The magnitude of the average velocity, in the time it completes the small angular displacement θ is 

The length of solenoid is I whose windings are made of material of density D and resistivity p. The winding resistance is R. The inductance of solenoid is
[m = mass of winding wire, µ₀ = permeability of free space]

The radius of a soap bubble is blown up to double its value under isothermal conditions. If 'r' be the initial radius of the bubble, and T be the surface tension, then energy spent in doubling the radius is ______

Surface density of charge on a charged conducting sphere of radius R in terms of electric field intensity E at a distance r in free space is ____________.

(r > R, ε₀ = permittivity of free space)

A winding wire which is used to frame a solenoid can bear a maximum of 20 A current. If the length of the solenoid is 80 cm and its cross-sectional radius is 3 cm, then the required length of winding wire is ______ (B = 0.2 T)

A toroid has a core (non-ferromagnetic) of inner radius 25 cm and outer radius 26 cm, around which 2,000 turns of a wire are wound. If the current in the wire is 10 A, the magnetic field inside the core of the toroid will be ______

The moment of inertia of a uniform thin rod of length L and mass M about an axis passing through a point at a distance of L/3 from one of its ends and perpendicular to the rod is ______

A ball is thrown vertically down from height of 80 m from the ground with an initial velocity 'v'. The ball hits the ground, loses `1/6`th of its total mechanical energy, and rebounds back to the same height. If the acceleration due to gravity is 10 ms^-2, the value of 'v' is

Three points masses, each of mass m are placed at the corners of an equilateral triangle of side l. The moment of inertia of the system about an axis passing through one of the vertices and parallel to the side joining other two vertices, will be ______.