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

According to de-Broglie hypothesis, the wavelength associated with moving electron of mass 'm' is 'λ_e'· Using mass energy relation and Planck's quantum theory, the wavelength associated with photon is  'λ_p'. If the energy (E) of electron and photon is same then relation between 'λ_e' and 'λ_p' is ______.

In the study of transistor as an amplifier, the ratio of collector current to emitter current is 0.98 then the ratio of collector current to base current will be ______.

In switching circuit, transistor is in ON state. Values of I_C and I_B are 5.2 mA and 10 µA respectively and value of R_C is 1 k`Omega`. If V_cc is at 5.5 V, then V_CE is ______.

V_e, V_b, and V_e are emitter, base, and collector voltage respectively for npn transistor in CE mode. Amplifier works for the combination of biasing voltage equal to ______.

An electron of mass m and a photon have same energy E. The ratio of de-Broglie wavelengths associated with them is ( c being velocity of light) ______.

Two-point charges of + 0.2 µµC and -0.2 µµC are separated by 1 o8 m. What is the value of the electric field at an axial point at a distance of 0.1 m from their mid-point?

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 ____________.

Work done during the process of charging a conductor is stored in the form of electrostatic energy and is given by ____________.

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

The electrostatic potential inside a charged sphere is given as V = Ar² + B, where r is the distance from the centre of the sphere; A and B are constants. Then the charge density in the sphere 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.

A spherical conductor of radius 10 cm has a charge of 3.2 x 10^-7 C distributed uniformly. What is the magnitude of electric field at a point 15 cm from the centre of the sphere?

`(1/(4 pi epsilon_0) = 9 xx 10^9 "Nm"^2 // "C"^2)`

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

In case of dimensions of electric field and electric dipole moment the power of mass is respectively.