Click to Chat

1800-1023-196

+91-120-4616500

CART 0

• 0

MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
`        The work function of a photoelectric material is 4.0 eV. (a) What is the threshold wavelength? (b) Find the wavelength of light for which the stopping potential is 2.5 V.`
5 years ago

```							Sol. ∅ = 4 eV = 4 * 1.6 *10^-19 J
a) Threshold wavelength = λ
∅ = hcλ
⇒ λ = hC/∅ = 6.63 * 10^-34 *3 * 10^8/4 * 1.6 *10^-19 = 6.63 * 3/6.4 * 10^-27/10^-9 = 3.1 * 10^7 m = 310 nm.
b) Stopping potential is 2.5 V
E = ∅ + eV
⇒ hcλ = 4 * 1.6 * 10^-19 + 1.6 * 10^-19 * 2.5
⇒ λ = 6.63 *10^-34 *3 * 10^8/λ * 1.6 * 10^-19 = 4 + 2.5
⇒ 6.63 * 3 * 10^-26/1.6 * 10^-19 * 2.5 = 1.9125 * 10^-7 = 190 nm.

```
5 years ago
Think You Can Provide A Better Answer ?

## Other Related Questions on Modern Physics

View all Questions »  ### Course Features

• 101 Video Lectures
• Revision Notes
• Previous Year Papers
• Mind Map
• Study Planner
• NCERT Solutions
• Discussion Forum
• Test paper with Video Solution  ### Course Features

• 110 Video Lectures
• Revision Notes
• Test paper with Video Solution
• Mind Map
• Study Planner
• NCERT Solutions
• Discussion Forum
• Previous Year Exam Questions