Which of the following graphs may correctly represent the variation of current (l) with potential difference (V) across a zener diode?

1.		2.
3.		4.

Which of the following statements is incorrect about LED?

A combination of logic gates is shown in the circuit. If \(A\) is at \(0\) V and \(B\) is at \(5\) V, then the potential of \(R\) is:

1. \(0\) V
2. \(5\) V
3. \(10\) V
4. Any of these

How many minimum number of NOR gates are required to obtain an AND gate?

1. One

2. Two

3. Three

4. Five

The circuit shown below is an electrical analogue for which of the following logic gates?
        

1. AND gate

2. OR gate

3. NOT gate

4. NOR gate

What is the equivalent resistance across the terminals of the battery if the diodes are ideal?

What is the name of the logic gate represented by the following symbol?
             

1. NOR

2. OR

3. NAND

4. AND

The combination of gates shown in the diagram is equivalent to:
              

1. OR

2. AND

3. NAND

4. NOT

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.