The conductivity of a semiconductor increases with increase in temperature, because

In figure given below $V_0$ is the potential barrier across a $p-n$ junction, when no battery is connected across the junction

In figure given below, assuming the diodes to be ideal

A 220 V AC supply is connected between points $A$ and $B$ (figure). What will be the potential difference $V$ across the capacitor?

Hole is

The output of the given circuit in figure given below.

In the circuit shown in figure given below, if the diode forward voltage drop is 0.3 V, the voltage difference between A and B is

Truth table for the given circuit is

When an electric field is applied across a semiconductor

Consider an $n-p-n$ transitor with its base-emitter junction forward biased and collector base junction reverse biased. Which of the following statements are true?

Figure given below shows that transfer characteristics of a base biased CE transistor. Which of the following statements are true?

In a $n-p-n$ transistor circuit, the collector current is 10 mA . If 95 per cent of the electrons emitted reach the collector, which of the following statements are true?

In the depletion region of a diode

What happens during regulation action of a Zener diode?

To reduce the ripples in rectifier circuit with capacitor filter

The breakdown in a reverse biased $p-n$ junction is more likely to occur due to

Why are elemental dopants for Silicon or Germanium usually chosen from group XIII or group XV?

$\mathrm{Sn}, \mathrm{C}$ and $\mathrm{Si}, \mathrm{Ge}$ are all group XIV elements. Yet, Sn is a conductor, C is an insulator while Si and Ge are semiconductors. Why?

Can the potential barrier across a $p-n$ junction be measured by simply connecting a voltmeter across the junction?

Draw the output waveform across the resistor in the given figure.

The amplifiers $X, Y$ and $Z$ are connected in series. If the voltage gains of $X, Y$ and $Z$ are 10, 20 and 30 , respectively and the input signal is 1 mV peak value, then what is the output signal voltage (peak value)

(i) if DC supply voltage is 10 V ?

(ii) if DC supply voltage is 5 V ?

In a CE transistor amplifier, there is a current and voltage gain associated with the circuit. In other words there is a power gain. Considering power a measure of energy, does the circuit violate conservation of energy?

(i) Name the type of a diode whose characteristics are shown in figure. (a) and (b).

(ii) What does the point $P$ in fig. (a) represent?

(iii) What does the points $P$ and $Q$ in fig. (b) represent?

Three photo diodes $D_1, D_2$ and $D_3$ are made of semiconductors having band gaps of $2.5 \mathrm{~eV}, 2 \mathrm{eV}$ and 3 eV , respectively. Which ones will be able to detect light of wavelength $6000 \mathop A\limits^o$ ?

If the resistance $R_1$ is increased (see figure), how will the readings of the ammeter and voltmeter change?

Two car garages have a common gate which needs to open automatically when a car enters either of the garages or cars enter both. Devise a circuit that resembles this situation using diodes for this situation.

How would you set up a circuit to obtain NOT gate using a transistor?

Explain why elemental semiconductor cannot be used to make visible LEDs.

Write the truth table for the circuit shown in figure given below. Name the gate that the circuit resembles.

A Zener of power rating 1 W is to be used as a voltage regulator. If Zener has a breakdown of 5 V and it has to regulate voltage which fluctuated between 3 V and 7 V , what should be the value of $R_s$ for safe operation (see figure)?

If each diode in figure has a forward bias resistance of $25 \Omega$ and infinite resistance in reverse bias, what will be the values of the currents $I_1, I_2, I_3$ and $I_4$ ?

In the circuit shown in figure, when the input voltage of the base resistance is $10 \mathrm{~V}, V_{\mathrm{BE}}$ is zero and $V_{\mathrm{CE}}$ is also zero. Find the values of $I_B, I_c$ and $\beta$.

Draw the output signals $C_1$ and $C_2$ in the given combination of gates.

Consider the circuit arrangement shown in figure for studying input and output characteristics of $n-p-n$ transistor in CE configuration. Select the values of $R_B$ and $R_C$ for a transistor whose $V_{\mathrm{BE}}=0.7 \mathrm{~V}$, so that the transistor is operating at point $Q$ as shown in the characteristics (see figure).

Given that the input impedance of the transistor is very small and $V_{C C}=V_{B B}=16 \mathrm{~V}$, also find the voltage gain and power gain of circuit making appropriate assumptions.

Assuming the ideal diode, draw the output waveform for the circuit given in fig. (a), explain the waveform.

Suppose a $n$-type wafer is created by doping Si crystal having $5 \times 10^{28}$ atoms $/ \mathrm{m}^3$ with 1 ppm concentration of As. On the surface 200 ppm boron is added to create ' $p$ ' region in this wafer. Considering $n_i=1.5 \times 10^{16} \mathrm{~m}^{-3}$, (i) Calculate the densities of the charge carriers in the $n$ and $p$ regions. (ii) Comment which charge carriers would contribute largely for the reverse saturation current when diode is reverse biased.

An X-OR gate has following truth table.

It is represented by following logic relation $Y=\bar{A} \cdot B+A \cdot \bar{B}$

Build this gate using AND, OR and NOT gates.

Consider a box with three terminals on top of it as shown in figure.

Three components namely, two germanium diodes and one resistor are connected across these three terminals in some arrangement. A student performs an experiment in which any two of these three terminals are connected in the circuit shown in figure. The student obtains graphs of current-voltage characteristics for unknown combination of components between the two terminals connected in the circuit. The graphs are

(i) when $A$ is positive and $B$ is negative

(ii) when A is negative and B is positive

(iii) when B is negative and C is positive

(iv) when B is positive and C is negative

(v) when A is positive and C is negative

(vi) when A is negative and C is positive

From these graphs of current - voltage characteristic shown in fig. (c) to (h) determine the arrangement of components between $A, B$, and $C$.

For the transistor circuit shown in figure, evaluate $V_E, R_B, R_E$, given $I_C=1 \mathrm{~mA}, V_{C E}=3 \mathrm{~V}, V_{B E}=0.5 \mathrm{~V}$ and $V_{C C}=12 \mathrm{~V}, \beta=100$.

In the circuit shown in fig. (a), find the value of R$_C$.