(a) What is photo electric effect ? State the laws of photo - electric emission.
(b) Show that de - Broglie wavelength of electron when accelerated through a potential difference V is given by the relation -
`lamda=(12.27)/sqrtVÅ` , where V is in volt.

Explanation

### Step-by-Step Text Solution

#### (a) What is the photoelectric effect? State the laws of photoelectric emission.

**Definition of Photoelectric Effect:**
The photoelectric effect is a phenomenon where electrons are emitted from a material (usually a metal) when it is exposed to light of a certain frequency. This frequency must be greater than a specific threshold frequency unique to the material. When light photons strike the surface of the metal, they can transfer energy to the electrons, causing them to be ejected from the surface. The emitted electrons are known as photoelectrons, and their flow generates a measurable electric current in a circuit.

**Laws of Photoelectric Emission:**
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