HSC Science (Computer Science) १२ वीं कक्षा - Maharashtra State Board Important Questions

A photocell is used to automatically switch on the street lights in the evening when the sunlight is low in intensity. Thus it has to work with visible light. The material of the cathode of the photocell is ______.

What is the photoelectric effect?

The threshold wavelength of tungsten is 2.76 x 10^-5 cm.
(a) Explain why no photoelectrons are emitted when the wavelength is more than 2.76 x 10^-5 cm.
(b) What will be the maximum kinetic energy of electrons ejected in each of the following cases

(i) if ultraviolet radiation of wavelength λ = 1.80 × 10^-5 cm and
(ii) radiation of frequency 4 x 10¹⁵ Hz is made incident on the tungsten surface?

What do you understand by the term wave-particle duality? Where does it apply?

The de Broglie wavelengths associated with an electron and a proton are the same. What will be the ratio of

1. their momenta
2. their kinetic energies?

According to De-Broglie, the waves are associated with ______ 

Planck's constant is 6.6 × 10^-34 Js. The momentum of each photon is given radiation Is 3.3 × 10^-29 kg/s. The λ of radiation is ______.

Define photoelectric effect. 

The minimum frequency for photoelectric effect on metal is 7 × 10¹⁴ Hz, Find the work function of the metal. 

If the total energy of radiation of frequency 10¹⁴ Hz is 6.63 J, Calculate the number of photons in the radiation. 

An electron is accelerated through a potential of 120 V. Find its de Broglie wavelength.

State Einstein photoelectric equation. 

What is the photoelectric effect? Define stopping potential and photoelectric work function. 

Calculate De Broglie's wavelength of the bullet moving with speed 90m/sec and having a mass of 5 gm. 

Explain De Broglie’s Hypothesis.

With the help of a circuit diagram describe the experiment to study the characteristics of the photoelectric effect. Hence discuss any 2 characteristics of the photoelectric effect.  

Is it always necessary to use red light to get a photoelectric effect?

Explain de-Broglie wavelength.

Obtain an expression for de-Broglie wavelength of wave associated with material particles. The photoelectric work function for metal is 4.2 eV. Find the threshold wavelength.

If the maximum kinetic energy of emitted electrons in the photoelectric effect is 2eV, the stopping potential will be ______.