Semiconductor Electronics

The output of the circuit is low (zero) for : [figure] Choose the correct answer from the options given below :

1. (A), (B) and (C) only
2. (A), (C) and (D) only
3. (B), (C) and (D) only
4. (A), (B) and (D) only

What is the current through the battery in the circuit shown below? [figure]

1. 1.5 A
2. 0.25 A
3. 1.0 A
4. 0.5 A

Which of the following circuits represents a forward biased diode? [figure] Choose the correct answer from the options given below:

1. (C) and (E) only
2. (A) and (D) only
3. (B), (D) and (E) only
4. (B), (C) and (E) only

[figure] To obtain the given truth table, following logic gate should be placed at G :

1. NOR Gate
2. OR Gate
3. AND Gate
4. NAND Gate

A light emitting diode (LED) is fabricated using GaAs semiconducting material whose band gap is 1.42 eV. The wavelength of light emitted from the LED is :

1. 1243 nm
2. 875 nm
3. 650 nm
4. 1400 nm

[figure] In the truth table of the above circuit the value of X and Y are :

1. 1, 1
2. 0, 1
3. 1, 0
4. 0, 0

The I–V characteristics of an electronic device are shown in the figure. The device is : [figure]

1. a solar cell
2. a transistor which can be used as an amplifier
3. a diode which can be used as a rectifier
4. a zener diode which can be used as a voltage regulator

The output Y of following circuit for given inputs is : [figure]

1. A B
2. A B
3. A B(A + B)
4. 0

A potential divider circuit is connected with a dc source of 20 V, a light emitting diode of glow in voltage 1.8 V and a zener diode of breakdown voltage of 3.2 V. The length (PR) of the resistive wire is 20 cm. The minimum length of PQ to just glow the LED is cm. [figure]

The correct truth table for the following logic circuit is : [figure]

1. [figure]
2. [figure]
3. [figure]
4. [figure]