Consider the following statements:1. The efficiency of a light emitting diode (LED) decreases with the injected current.2. The efficiency of a LED increases with a decrease in temperature.3. The light emitted is connected near the junction because most of the carriers are within a diffusion length of the junction.4. Light is emitted in a LED when electrons move from the valence band to the conduction band.Which of these statements are correct?

Consider the following statements:1. The efficiency of a light emittin

1.	Consider the following statements:1. The efficiency of a light emitting diode (LED) decreases with the injected current.2. The efficiency of a LED increases with a decrease in temperature.3. The light emitted is connected near the junction because most of the carriers are within a diffusion length of the junction.4. Light is emitted in a LED when electrons move from the valence band to the conduction band.Which of these statements are correct?
A.	1, 2. 3 and 4
B.	1 and 2 only
C.	3 and 4 only
D.	2 and 3 only
Answer» E.

Discussion

No Comment Found

Related MCQs

Directions: Each item consists of two statements, one labeled as ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answer using the code given below:Statement (I): Solar insolation is a measure of solar irradiance over a specified period of time.Statement (II): Solar insolation data are commonly used for isolated PV system design.
If a RED/GREEN multi-colour LED is switched fast enough between two polarities, it will produce ________ colour.
Direction: Question consists of two statements, one labeled as the 'Assertion (A)' and the other as 'Reason (R)'. Examine these two statements carefully and select the answer to this question using the codes given below:Assertion (A): Many semiconductors where minimum energy in the conduction band and maximum energy in the valence band occur at the same value of \(\mathop k\limits^ \to \) (wave vector), are preferred for optical lenses.Reason (R): For such semiconductors, the efficiency of carrier generation and recombination is very high.
______ is a type of photo detector, which can convert optical signals into electrical signals.
A PIN diode consists of:
Consider the following statements:The main contribution to photoconduction is by1. the generation of electron and hole pair by a photon2. a donor electron jumping into the conduction band because of a photon’s energy3. a valence electron jumping into an acceptor state because of a photon’s energyWhich of the above statements is/are correct?
An LED has a rating of 2 V and 10 mA. If it is connected to a 6V battery, the minimum value of series resistance is
Assertion (A): A p-n junction diode with low junction depth can be used as a solar cell when illuminated by suitable light (wavelength) at the top thin layer above the junction.Reason (R): A p-n junction diode under no condition can be used as a solar cell. It can be used only as a light-emitting diode for optoelectronic applications.
Light wave propagation is possible in optical fibre due to a phenomenon called:
Match List I with List-II and select the correct answer using the code given below the lists: List I List IIA. LED1. Electrical isolatorB. LCD2. Forward biasedC. Optocouplers3. Light reflectors / transmittersD. Photodiode4. Reverse biased

Discussion

No Comment Found

Related MCQs

Reply to Comment