## Question

### Solution

Correct option is

Using bragg’s law,

.

#### SIMILAR QUESTIONS

Q1

The threshold frequency for a metal is . Light of frequency  falls on the metal. What will be the cut-off voltage for photoelectric emission.

Q2

The work function of caesium is 2.14 eV. Find the threshold frequency for caesium.

Q3

In an experiment on photoelectric emission, following observations were made wavelength of the incident light

Q4

Light of wavelength 2000 Å falls on aluminium surface (work function of aluminium is .2 eV). Calculate cut-off wavelength for aluminium. Take,

.

Q5

Monochromatic radiation of wavelength 640.2 nm (1 nm = 10–9m) from a neon lamp irradiates a photosensitive material made of cesium or tungsten. The stopping voltage is measured to be 0.54 V. The neon surface is replaced by an iron source whose 427.2 nm line irradiates the material. Predict the new stopping voltage.

Q6

The first emission line in the atomic spectrum in the Ballmer series appears at:

Q7

A 200g rickets ball is thrown with a speed of 3 cm/sec. what will be its de Broglie Wavelength

Q8

If the X-rays tulie is working at 20kv. Then the minimum wavelentgth of X – rays will be.

Q9

An X – rays tulie is operating at 15kv. The lower limit of the wavelength of X – rays produced is:

Q10

The frequency of the line k line of the characteristtis X – rays spectrum is proportional to.