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

If the maximum kinetic energy of emitted electrons in photoelectric effect is 3.2 × 10^-19 J and the work-function for metal is 6.63 × 10^-19 J, then stopping potential and threshold wavelength respectively are
[Planck's constant, h = 6.63 × 10³⁴ J-s]
[Velocity of light, c = 3 × 10⁸ `"m"/"s"`]
[Charge on electron= 1.6 × 10^-19 C]

An alternating voltage e = `200sqrt2` sin(100 t) volt is connected to a 1 µF capacitor through a.c. ammeter. The reading of the ammeter is ______

Two waves represented by the following equations are travelling in the same medium 

`y_1 = 5 sin 2pi(75t - 0.25 x)`

`y_2 = 10 sin 2pi(150t - 0.50 x)`

The intensity ratio `"I"_1/"I"_2` of the two waves is ______

The temperature of an ideal gas, initially at 27°C, is raised by 12°C. The rms velocity of the gas molecules will, ______ 

The Gyromagnetic ratio of the electron revolving in a circular orbit of a hydrogen atom is 8.8 x 10¹⁰ C kg^-1. What is the mass of the electron? (Given charge of the electron = 1.6 x 10-19 C.) 

The angle made by orbital angular momentum of electron with the direction of the orbital magnetic moment is ______.

Dimensions of Gyromagnetic ratio are _________.

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

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

For photoelectric emission from certain metal, the cut-off frequency is v. If radiation of frequency 2v impinges on the metal plate, the maximum possible velocity of the emitted electron will be (m is the electron mass) ____________.

In a spring-block system, length of the spring is increased by 5%. The time period will ____________.

The rms value of current in a 50 Hz AC circuit is 6 A. The average value of AC current over a cycle is ____________.

When a light of wavelength 4000 Å falls on a photoelectric emitter, photoelectrons are liberated. For another emitter, light of wavelength 6000 Å is sufficient for photo emission. The work functions of the two emitters are in the ratio of ____________.

Threshold frequency for a metal is 10¹⁵ Hz. Light of `lambda` = 4000 Å falls on its surface. Which of the following statements is correct?

A metal surface is illuminated by light of given intensity and frequency to cause photoemission. If the intensity of illumination is reduced to one-fourth of its original value then the maximum KE of the emitted photoelectrons would be ______.

A particle is performing a linear simple harmonic motion of amplitude 'A'. When it is midway between its mean and extreme position, the magnitudes of its velocity and acceleration are equal. What is the periodic time of the motion?

The work function of a metal is 1.6 x 10^-19 J. When the metal surface is illuminated by the light of wavelength 6400 Å, then the maximum kinetic energy of emitted photo-electrons will be (Planck's constant h = 6.4 x 10^-34 Js) ____________.

An electron revolving in a circular orbit of radius 'r' with velocity 'v' and frequency v has orbital magnetic moment 'M'. If the frequency of revolution is tripled then the new magnetic moment will be ____________.

The equation of standing wave is y = a cos kx sin `omega"t"`. Which one of following graphs is for the wave at t = T/4?

The critical angle for light going from medium 'x' to medium 'y' is 'θ'. The speed of light in medium 'x' is 'v_x'. The speed of light in medium 'y' is ______.