LED's have following advantages over incandescent low power lamps.
A. Low operational voltage and less power.
B. No warm up time required.
C. LED must at least have a band gap of 1.8 eV.
D. $GaAs_{1-x} P_x$ is used for making LED's of different colours
E. The band width of emitted light in LED's is 100 Å to 500 Å
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → All correct
- LED's operate at low voltages and there by consume significantly less power.
- Unlike incandescent lamps, LED's reach full brightness immediately, without any warm-up period.
- A band gap of around 1.8 eV is typically necessary for efficient light emission in LED's.
- The emitted light from LED's has a relatively narrow bandwidth, usually in a range of 100°A - 500°A.
- Gallium arsenide phosphide is commonly used to produce LED's of various colours.