Dual Nature of ...

2mW light of wave length 4400 Å is incident on photo sensitive surface of Cs. If quantum efficiency is 0.5 %, what will be the value of photoelectric current ?

A proton, a deutron and an a-particle having the same momentum, enters a region of uniform electric field between the parallel plates of a capacitor. The electric field is perpendicular to the initial path of the particles. Then the ratio of deflections suffered by them is

In the following agreement y = 1.0 mm, d = 0.24 mm and D = 1.2 m. The work function of the material of the emitter is 2.2 eV. The stopping potential V needed to stop the photon is ..........

Assertion : Stopping potential is a measure of K.E. of photo-electrons.
Reason : W = eV_s = 1/2 mv² = K. E

Assertion : Metals like Na or K, emit electrons even when visible lights fall on them .
Reason : This is because their work function is low.

Assertion : The de Broglie wavelength of an electron accelerated through 941 volts is 0.4 Å
Reason : Higher the acceleration potentials of electron, smaller is the de Broglie wavelength.

Threshold - Frequency is equal to = ................ × 10¹⁴ Hz.

An electron is accelerated under a potential difference of 64 V, the de Broglie wave length associated with electron is = ............. Å
(Use charge of electron = 1.6 × 10^–19 C, C = 9.1 × 10^–31 Kg, mass of electron h = 6.623 × 10^–34 J.sec))

A α particle and proton has same K.E. The ratio of de Broglie wavelength of a α - particle and proton is....

If α particle and proton have same momenta, the ratio of de Broglie wavelength of α -particle and proton is.....