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

A common emitter amplifier circuit built using an n-p-n transistor is shown in the figure. Its DC current gain is 300, R_C = 4 kΩ and V_CC = 20 V. What is the minimum base current for V_CE to reach saturation?

The base current in common emitter mode of the transistor changes by 10 µA. If the current gain of the transistor is 50, then change in collector current is ______.

The transfer ratio of a transistor is 50. The input resistance of the transistor when used in the CE configuration is 1K Ω. The peak value for an AC input voltage of 0.01 V of collector current is ______.

If a string fixed at both ends vibrates in four loops. The wavelength is 10 cm. The length of string is ______.

The energy of photon corresponding to a radiation of wavelength 600 nm is 3.32 × 10⁻¹⁹ J. The energy of a photon corresponding to a wavelength of 400 nm is ______. 

The current amplification factor for a transistor in its common emitter mode is 50. The current amplification factor in the common base mode of the transistor is ______.

In Huygens' wave theory, the locus of all points in the same state of vibration is called ______.

The direction of wavefront of a wave with the wave motion is ______.

The maximum velocity of the photoelectron emitted by the metal surface is v. Charge and the mass of the photoelectron is denoted by e and m, respectively. The stopping potential in volt is ______.

The energy of the incident photon on the metal surface is 3 W and then 5 W, where W is the work function for that metal. The ratio of velocities of emitted photoelectrons is ______.

Two waves Y₁ = 0.25 sin 316 t and Y₂ = 0.25 sin 310 t are propagating along the same direction. The number of beats produced per second are ______.

The maximum velocity of photoelectron emitted is 4.8 m/s. If the e/m ratio of the electron is 1.76 × 10¹¹ C/kg, then stopping potential is given by ______ 

The light of wavelength '`lambda`'. incident on the surface of metal having work function `phi` emits the electrons. The maximum velocity of electrons emitted is ______.
[c = velocity of light, h = Planck's constant, m = mass of electron]

Which of the following instruments is not a direct reading instrument?

In a series LCR circuit R = 300 Ω, L = 0.9 H, C = 2 µF, ω = 1000 rad/s. The impedance of the circuit is ______

The ratio of energies of photons produced due to transition of electron of hydrogen atom from its (i) second to first energy level and (ii) highest energy level to second level is respectively.

As we go from the equator of the earth to pole of the earth, the value of acceleration due to gravity ______.

How the linear velocity 'v' of an electron in the Bohr orbit is related to its quantum number 'n'?

The kinetic energy of the most energetic photoelectron emitted from a metal surface is doubled when the wavelength of the incident radiation is reduced from λ₁ to λ₂. The work function of the metal is ______

The internal energy of a system is ______