Which one of the following is not true for the photodiodes?

1.	The current in the forward bias is more than the current in the reverse bias.
2.	Photodiodes are preferably used in the reverse bias condition for measuring light intensity.
3.	Photodiodes are preferably used in the forward bias condition for measuring light intensity
4.	In photodiodes, only a small portion of the incident photons gets converted to electric current.

The diagram shows graph of current versus voltage for a material. The material can be a:

1. Conductor

2. Insulator

3. Diode

4. None of the above

Which material is preferred for solar cells?
1. \(\text{Si}\)
2. \(\text{GaAs}\)
3. \(\text{CdS}\)
4. both \(\text{Si}\) and \(\text{GaAs}\)

Graph shows barrier potential for a p-n junction diode under different biasing conditions where V_o is the built-in potential of the diode. Then graph 2 represents:

1. Forward biasing with low voltage battery

2. Forward biasing with high voltage battery

3. Reverse biasing

4. Unbiased condition

The output characteristics of a transistor are shown in the figure. When $V_{CE}$ is \(10\) V and $I_C$  = \(4.0\) mA, the value of ${\beta }_{ac}$ is:

1. \(200\)
2. \(250\)
3. \(150\)
4. \(100\)

The output waveform \((Y) \)of the AND gate for the following inputs \(A\) and \(B \) given in the figure, is:

1.
2.
3.
4.	None of these

The output waveform \((Y)\) of the NAND gate for the following inputs \(A\) and \(B\) given in the figure is:

1.
2.
3.
4.	none of these

For a Silicon CE transistor amplifier, the audio signal voltage across the collector resistance of 2.0 k$\Omega$ is 2.0 V. Suppose the current amplification factor of the transistor is 100, what should be the value of ${\mathrm{R }}_{}$ in series with the supply of 2.0 V if the dc base current has to be 10 times the signal current?

$1. 18 k\Omega$
$2. 16 k\Omega$
$3. 12 k\Omega$
$4. 14 k\Omega$

For a Silicon CE transistor amplifier, the audio signal voltage across the collector resistance of 2.0 k$\Omega$ is 2.0 V. Suppose the current amplification factor of the transistor is 100 if the dc base current has to be 10 times the signal current. The dc current across through the collector resistance will be:

1. 0.1 mA

2. 10 mA

3. 1.0 mA

4. 0.01 mA

In figure, the $V_{BB}$ supply can be varied from 0 V to 5.0 V. The Si transistor has ${\beta }_{dc}$ = 250 and $R_B$= 100 k$\Omega$, $R_C$ = 1 K$\Omega$, $V_{CC}$= 5.0 V. Assume that when the transistor is saturated, $V_{CE}$ = 0 V and $V_{BE}$= 0.8V. The minimum base current, for which the transistor will reach saturation is:

 $1. 20 \mu A$
$2. 5 mA$
$3. 20 mA$
$4. 5 \mu A$