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

The wavelength of two waves are 50 and 51 cm respectively. If the temperature of the room is 20°C then what will be the number of beats produced per second by these waves, when the speed of sound at 0°C is 332 m/s?

The width of a slit is 0.012 mm. Monochromatic light is incident on it. The angular position of first bright line is 5.2°. The wavelength of incident light is ______. [sin 5.2° = 0.0906].

A common emitter amplifier has a voltage gain of 50, an input impedance of 100Ω and an output impedance of 2000Ω. The power gain of the amplifier is ______.

A transistor is used as a common emitter amplifier with a load resistance 2 KΩ. The input resistance is 150 Ω. Base current is changed by 20 µA which results in a change in collector current by 1.5 mA. The voltage gain of the amplifier is ______. 

A conducting wire has length 'L₁' and diameter 'd₁'. After stretching the same wire length becomes 'L₂' and diameter 'd₂' The ratio of resistances before and after stretching is ______.

For a transistor,  α_dc and β_dc are the current ratios, then the value of `(beta_"dc"-delta_"dc")/(alpha_"dc".beta_"dc")` 

In communication system, the process of superimposing a low frequency signal on a high frequency wave is known as ______.

A bar magnet has length 3 cm, cross-sectional area 2 cm³ and magnetic moment 3 Am². The intensity of magnetisation of bar magnet is ______.

A resistance of 20 Ω is connected in the left gap of a meter bridge and an unknown resistance greater than 20 Ω is connected in the right gap. When these resistances are interchanged, the balance point shifts by 20 cm. The unknown resistance is ______.

For an insulator, the forbidden energy gap is ______.

A source of 300 Hz frequency, an observer and a wind are moving as shown in the figure with respect to the ground. The frequency heard by observation is ______.

(Take, the speed of sound in air = 340 m/s)

Two instruments having stretched strings are being played in unison. When the tension of one of the instruments is increased by 1%, 3 beats are produced in 2 s. The initial frequency of vibration of each wire is ______.

An astronaut is approaching the moon. He sends out a radio signal of frequency 5000 MHz and the frequency of echo is different from that of the original frequency by 100 kHz. His velocity of approach wrt, to the moon, is ______.

Transverse waves are generated in two steel wires A and B with a source of 512 Hz. If their diameters are in the ratio 2 : 1 and tensions are in the ratio 2 : 1, the velocities of the waves are in the ratio (wires A and B) ______.

A progressive wave of frequency 500 Hz is travelling with a velocity of 360 m/s. How far apart are two points 60° out of phase?

The figure below shows a balanced Wheatstone network. If it is disturbed by changing P to 22Ω, then which of the following steps will bring the bridge again to a balanced state?

In a p-n-p transistor circuit, the collector current is 10 mA. If 90% of the holes emitted from the emitter reach the collector, ______.

Wave of frequency 500 Hz has a phase velocity 360 ms^-1. The phase difference between two displacement at a certain point at time 10^-3 s apart will be ______.

A nucleus of rest splits into two nuclear parts having radii in the ratio 1 : 2. Their velocities are in the ratio.

The reverse bias in a junction diode is changed from 8V to 13V, then the value of the current changes from 40μA to 60μA. The resistance of junction diode will be ______.