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

In the metre bridge experiment shown in the figure, the balance length AC corresponding to null deflection of the galvanometer is x. What would be the balance length if the radius of the wire AB is doubled?

An iron rod of cross-sectional area 6 sq. cm is placed with its length parallel to a magnetic field of intensity 1200 Alm. The flux through the rod is 60 x 10^-4 Wb. The permeability of the rod is ______.

Coercivity of a magnet where the ferromagnet gets completely demagnetized is 6 x 10³ Am^-1. The minimum current required to be passed in a solenoid having 2000 turns per metre, so that the magnet gets completely demagnetized when placed inside the solenoid is ____________.

A bar magnet has coercivity 6 x 10³ Am^-1. It is desired to demagnetise it by inserting it inside a solenoid 10 cm long and having 40 turns. The current that should be sent through the solenoid is ____________.

In Wheatstone's bridge P = 7 ohm, Q = 12 ohm, R = 3 ohm and S = 8 ohm. How much resistance must be put in parallel to the resistance S to balance the bridge?

In case of vibrating string, the frequency of the fifth harmonic is equal to frequency of the ____________.

On interchanging the resistances, the balance point of a metre bridge shifts to the left by 10 cm. The resistance of their series combination is 1 k`Omega`. How much was the resistance on the left slot before interchanging the resistances?

The frequency of a tuning fork is 384 per second and velocity of sound in air is 352 m/s. How far the sound has traversed while fork completes 48 vibration?

In Wheatstone's network p = 2 `Omega` , Q = 2 `Omega`, R = 2 `Omega` and S = 3 `Omega`. The resistance with which S is to be shunted in order that the bridge may be balanced is ______.

An iron rod is placed parallel to magnetic field of intensity 4000 A/m. The magnetic flux through the rod is 8 x 10^-4 Wb and its cross-sectional area is 4 cm² . The magnetic permeability of the rod in Wb/A - m is ____________.

The permeability of a metal is 0.01256 TmA^{- 1}  What is its relative permeability?

ln the metre bridge experiment, one metre long wire acts as ____________.

The resistances in left and right gap of a metrebridge are 20 `Omega` and 30 `Omega` respectively. When the resistance in the left gap is reduced to half its value, the balance point shifts by ______.

The magnetic field (B) inside a long solenoid having 'n', turns per unit length and carrying current 'I' when iron core is kept in it is (`mu_0` = permeability of vacuum, `chi` = magnetic susceptibility) ____________.

In the Wheatstone bridge, (shown in the figure) X = Y and A > B. The direction of the current between a and b will be ____________.

What is the e.m.f of the cell C in the circuit shown in figure, if the deflection in the galvanometer is zero, the resistance of the wire is 3 `Omega`, The length of the wire is 100 cm?

The wave of the wavelength 30 cm and frequency 100 Hz will be ______.

If a lens is cut into two pieces perpendicular to the principal axis and only one part is used, the intensity of the image will be ____________.

When the value of R in the balanced Wheatstone bridge, shown in the figure, is increased from 5 `Omega` to 7 `Omega`, the value of s has to be increased by 3 `Omega` in order to maintain the balance. What is the initial value of S?

Wavefront is the locus of all points, where the particles of the medium vibrate with the same ____________.