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

A force F acts between sodium and chlorine ions of salt (sodium chloride) when put 1 cm apart in air. The permittivity of air and dielectric constant of water are `epsilon_0` and K respectively. When a piece of salt is put in water, electrical force acting between sodium and chlorine ions 1 cm apart is ____________.

If `alpha`-current gain of a transistor is 0.98. What is the value of `beta`- current gain of the transistor?

What is the momentum of a photon having frequency 1.5 x 10¹³ Hz?

The force between two charges 0.06 m apart is 5 N. If each charge is moved towards the other by 0.01 m, then the force between them will become ______.

In an npn transistor, the base current is 100 µA and the collector current is 10 mA. The emitter current is ______.

The electric force acting between two point charges kept at a certain distance in vacuum is 16 N. If the same two charges are kept at the same distance in a medium of dielectric constant 8, the electric force acting between them is ____________ N.

A total charge Q is broken in two parts Q₁ and Q₂ and they are placed at a distance R from each other. The maximum force of repulsion between them will occur, when ____________.

In an npn transistor, the collector current is 24 mA. If 80% of electrons reach collector, its base current in mA is ______.

ln switching circuit, transistor is in ON state and values of I_C and I_B are 4.2 mA and 5 µA respectively and R_C= l k`Omega` and R_B= 300 k`Omega`. If V_BE = 0.5 V, find the value of V_BB.

In a transistor in CE configuration, the ratio of power gain to voltage gain is ____________.

In switching circuit, transistor is in ON state, values of I_E and l_B are 10 mA and 0.8 mA respectively and R_L is 2 k`Omega`. If V_CE is 7.6 V, then V_CC is ____________.

Which of the following regions of a transistors are, respectively, heavily dopped and lightly dopped?

In a common emitter amplifier circuit using an n-p-n transistor, the phase difference between the input and the output voltages will be: ____________.

If the radius of the circular path and frequency of revolution of a particle of mass m are doubled, then the change in its kinetic energy will be (E_i and E_f are the initial and final kinetic energies of the particle respectively.)

In case of npn transistors, the collector current is always less than the emitter current because ______.

The depletion layer in the p-n junction diode is caused by ______.

A particle of charge q, mass m and energy E has de-Broglie wavelength `lambda.` For a particle of charge 2q, mass 2m and energy 2E, the de-Broglie wavelength is ____________.

Polarised dielectric is equivalent to ______.

In an npn transistor circuit, the collector current is 10 mA. If 90% of the electrons emitted reach the collector, the emitter current (I_E) and base current (I_B) are given by ____________.

How much energy is imparted to an electron so that its de-Broglie wavelength reduces from 10^-10 m to 0.5 × 10^-10 m? (E =energy of electron)