In the Davisson and Germer experiment, the velocity of electrons emitted from the electron gun can be increased by:

In the Davisson and Germer experiment, how can we increase the velocity of electrons emitted from the electron gun?

On which surface is the electron beam made to fall in the Davisson-Germer experiment?

1. Iron crystals

2. Nickel crystals

3. Gold crystals

4. Cesium crystals

Which among the following verified the wave nature of electrons experimentally?

1. De-Broglie 

2. Hertz

3. Einstein 

4. Davisson and Germer 

Consider the figure given below. Suppose the voltage applied to A is increased. The diffracted beam will have the maximum at a value of $\mathrm{\theta }$ that
                  
1. will be larger than the earlier value

2. will be the same as the earlier value

3. will be less than the earlier value 

4. will depend on the target