For the logic circuit given below, the output Y for A=0, B=0 and A=1, B=1 are:

1. 0 and 1

2. 0 and 0

3. 1 and 0

4. 1 and 1

A photocell is illuminated by a point source of radiation 4 m away. If the same source is kept 8 m away, then the number of photoelectrons emitted:

1. becomes four times the initial value.

2. becomes one-fourth of the initial value.

3. remains unchanged.

4. becomes half of the initial value.

A Zener diode is used to obtain a constant voltage. If applied voltage \(\text V\) changes, then:
(\(\text V\) is more than Zener voltage)
             

Which one of the following represents an analog circuit diagram for OR gate?

1.		2.
3.		4.

Which of the following-junction is used unbiased?

1. Photo diode

2. LED

3. Zener diode

4. Solar cell

In the given circuit, the power developed in 2 k$\Omega$ resistor is:

1. 36 mW

2. 12 mW

3. 144 mW

4. 72 mW

Current $I_1$ through the Zener diode shown in the circuit is:
      
1. Zero
2. 0.6 mA
3. 0.2 mA
4. 0.8 mA

The output of the OR gate is 1:

1. only if both inputs are zero.

2. if either or both inputs are 1.

3. only if both inputs are 1.

4. if any of the inputs is zero.

In the circuit shown, $I_1 and I_2$ are respectively:
(If diodes are ideal)

1. 0, 0

2. 5 mA, 5 mA

3. 5 mA, 0

4. 0, 5 mA

The LED:

1. is reverse-biased.

2. is forward-biased.

3. can be made of GaAs.

4. both (2) & (3) are correct.