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

L-C-R series circuit contains a resistance of 10 Ω and self-inductance 0.4 H connected in series with variable capacitor across 60 V and 50 Hz supply. The value of capacity at resonance will be π² = 10.

For a common emitter configuration, if 'α' and 'β' have their usual meanings, the correct relationship between 'α' and 'β' is ______.

In a silicon transistor, a change of 7.89 mA in the emitter current if produces a change of 7.8 mA in the collector current, then the base current must change by ____________.

In a transistor, a change of 8.0 mA in the emitter current produces a change of 7.8 mA in the collector current. Then change in the base current is ____________.

A transistor when connected in common emitter mode has a ____________.

A pnp transistor is used in common-emitter mode. If a change of 40 µA in base current brings a change of 2 µA in collector current with 0.04 V in base-emitter voltage, then the input resistance is ____________.

The current gain `alpha` of a transistor is 0.95. The change in collector current corresponding to a change of 0.4 mA in the base current in a common emitter arrangement is ______.

In a semiconductor diode, the barrier potential offers opposition to only ______.

To hear an echo, the total distance covered by sound from the point of generation to the reflecting surface and back should be atleast ____________.

In a transistor, the thickness of the base region ____________.

Two point charges +3 µC and +8 µC repel each other with a force of 40 N. If a charge of -5 µC is added to each of them, then force between them will become ______.

An alternating e.m.f. of 0.2 V is applied across an LCR series circuit having R = 4 `Omega`, C = 80 µF and L = 200 mH. At resonance the voltage drop across the inductor is ____________.

In series 'LR' circuit and in series 'RC' circuit, same current is flowing. If the frequency of e.m.f. of a.c. is increased for both the circuits, the impedance will ____________.

In series LCR circuit, resistance is 18 `Omega` and impedance is 33 `Omega`. An r.m.s. voltage of 220 V is applied across the circuit. The true power consumed in a.c. circuit is ____________.

In LCR series circuit, an alternating e.m.f. 'e' and current 'i' are given by the equations e = 100 sin (100 t) volt,

`"i" = 100  "sin" (100"t" + pi/3)"mA"`.

The average power dissipated in the circuit will be ____________.

The wavelength '`lambda`' of a photon and de-Broglie wavelength of an electron have same value. The ratio of energy of a photon to kinetic energy of electron is (m = mass of electron, c = velocity of light, h = Planck's constant) ____________.

If '`lambda_1`' and '`lambda_2`' are de-Broglie wavelengths for electrons in first and second Bohr orbits in hydrogen atom, then the ratio '`lambda_2`' to '`lambda_1`' is (E₁ = -13.6 eV) ____________.

If the kinetic energy of a particle is increased to 16 times its previous value, the percentage change in the de-Broglie wavelength of the particle is ____________.

Graph shows the variation of de-Broglie wavelength `(lambda)` versus `1/sqrt"V"`, where 'V' is the accelerating potential for four particles carrying same charge but of masses m₁ , m₂, m₃, m₄. Which particle has a smaller mass?

If the potential difference used to accelerate electrons is doubled, by what factor does the de-Broglie wavelength associated with the electrons change?