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

When a metal with work function 0.6 eV is illuminated with light of energy 2 eV, the stopping potential will be ____________.

When a photosensitive surface is irradiated by lights of wavelengths `lambda_1` and `lambda_2`, kinetic energies of emitted photoelectrons are E₁ and E₂ respectively. The work function of the photosensitive surface is ____________.

Two incident radiations having energies two times and ten times of the work function of a metal surface, produce photoelectric effect. The ratio of maximum velocities of emitted photo electrons respectively is ____________.

An electromagnetic wave of wavelength '`lambda`' is incident on a photosensitive surface of negligible work function. If the photoelectrons emitted from this surface have the de-Broglie wavelength '`lambda_1`' then ____________.

When light of wavelength '`lambda`' is incident on photosensitive surface, photons of power 'P' are emitted. The number of photons (n) emitted in 't' second is (h = Planck's constant, c = velocity of light in vacuum) ____________.

A metal surface having work function 'w₀' emits photoelectrons when photons of energy 'E' are incident on it. The electron enters the uniform magnetic field (B) in perpendicular direction and moves in circular path of radius 'r'. Then 'r' is equal to (m and e be the mass and charge of electron respectively) ____________.

An electron makes a transition from an excited state to the ground state of a hydrogen like atom. Out of the following statements which one is correct?

In hydrogen atom, during the transition of electron from n^th outer orbit to first Bohr orbit, a photon of wavelength `lambda` is emitted. The value of 'n' is [R =Rydberg's constant] ____________.

When an electron in hydrogen atom jumps from third excited state to the ground state, the de-Broglie wavelength associated with the electron becomes ____________.

Using Bohr's quantization condition, what is the rotational energy in the second orbit for a diatomic molecule. (I = moment of inertia of diatomic molecule, h = Planck's constant)

The de-Broglie wavelength of an electron in 4^th orbit is ______.

(r = radius of 1^st orbit)

In any Bohr orbit of hydrogen atom, the ratio of K.E to P.E of revolving electron at a distance 'r' from the nucleus is ______.

When an electron in a hydrogen atom jumps from the third orbit to the second orbit, it emits a photon of wavelength 'λ'. When it jumps from the fourth orbit to third orbit, the wavelength emitted by the photon will be ______.

Electron in Hydrogen atom first jumps from third excited state to second excited state and then from second excited state to first excited state. The ratio of the wavelengths λ₁ : λ₂ emitted in the two cases respectively is ______.

The electron of mass 'm' is rotating in first Bohr orbit of radius 'r' in hydrogen atom. The orbital acceleration of the electron in first orbit is ______.

(b =Planck's constant)

Which of the following represents isothermal process?

A straight wire of length 50 cm carrying a current of 6 A is suspended in mid-air by a uniform magnetic field of 0.4 T (as shown in figure). The mass of the wire is ______.

(g = 10` "ms"^-2`)

A straight conductor of length 2 m moves in a uniform magnetic field of induction 2.5 x `10^-3` T with a velocity. of 4 m/s in a direction perpendicular to its length and also perpendicular to the field. The e.m.f. induced between the ends of the conductor is ______.

In the potentiometer experiment, the balancing length with cell E₁ of unknown e.m.f. is ℓ₁ cm. By shunting the cell E₁ with resistance 'R' which is equal to internal resistance (r) of the cell E₁, the balancing length ℓ₂ is ______

A potentiometer is used to measure the potential difference between A and B, the null point is obtained at 0.9 m. Now the potential difference between A and C is measured, the null point is obtained at 0.3 m. The ratio `E_2/E_1` is (E₁ > E₂) ______