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

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?

In a transistor, doping level in base is increased slightly, the collector current and base current respectively ______.

In transistor amplifier, base-emitter junction is forward biased and collector emitter junction is reverse biased. The current gain is ______.

In the case of transistor, the relation between current ratios α_dc and β_dc is ______.

In common emitter mode of transistor, the d.c. current gain is 20, the emitter current is 7 mA. The collector current is ______.

A change of 9.0 mA in the emitter current brings a change of 8.9 mA in the collector current. The value of current gain β will be ______.

A transistor is connected in C - E mode. If collector current is 72 × 10^-5 A and α = 0.96, then base current will be ______.

An e.m.f. E = E₀ sin `omega`t is applied to a circuit containing 'L' and 'R' in series. If X_L = R, then the power dissipated in the circuit is ____________.

According to de-Broglie hypothesis, the ratio of wavelength of an electron and that of photon having same energy 'E' is (m = mass of electron, c = velocity of light) ____________.

The voltage gain of a CE amplifier is 50. A sinusoidal ac of amplitude 10 mV is applied as a signal. The output of the amplifier will be ______.

A photon of wavelength 3315 Å falls on a photocathode and an electron of energy 3 x 10^-19 J is ejected. The threshold wavelength of photon is [Planck's constant (h) = 6.63 x 10^-34 J.s, velocity of light (c) = 3 x 10⁸ m/s] ____________.