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

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] ____________.

The ratio of the forces between two small spheres with constant charge (a) in air (b) in a medium of dielectric constant K is ______.

For an ideal diode, the current in the following arrangement is ______.