Semiconductors and Diodes

In the following limiter circuit, an input voltage V_i = 10 sin 100 $\pi$t is applied. Assume that the diode drop is 0.7 V when it is forward biased. The zener breakdown voltage is 6.8 V. The maximum and minimum values of the output voltage respectively are

Assume that the $\beta$ of transistor is extremely large and V_BE = 0.7V, I_C and V_CE in the circuit are shown in the figure.

For an npn transistor connected as shown in figure, V_BE = 0.7 Volts. Given that reverse saturation current of the junction at room temperature 300°K is 10^-13 A, the emitter current is

In the amplifier circuit shown in figure, the values of R₁ and R₂ are such that the transistor is operating at V_CE = 3V and I_C = 1.5mA when its $\beta$is 150. For a transistor with $\beta$of 200, the operating point (V_CE, I_C) is

In the circuit shown below, assume that the voltage drop across a forward biased diode is 0.7 V. The thermal voltage V_t = kT / q = 25mV. The small signal input v_i = V_p cos $\omega t$ where V_p = 100 mV.

The bias current I_DC through the diodes is

The amplifier circuit shown below uses a silicon transistor. The capacitors C_C and C_E can be assumed to be short at signal frequency and the effect of output resistance R₀ can be ignored. If C_E is disconnected from the circuit, which one of the following statements is TRUE?

In the following transistor circuit, V_BE = 0.7 V, r₃ = 25 mV / I_E, and $\beta$ and all the capacitances are very large

The mid-band voltage gain of the amplifier is approximately

In the circuit shown below, for the MOS transistors, $\mu_n \ C_{ox}$ = 100$\mu A / V^2$and the threshold voltage V_T = 1V. The voltage V_x at the source of the upper transistor is

In the following transistor circuit, V_BE = 0.7 V, r₃ = 25 mV / I_E and $\beta$ and all the capacitances are very large.

The value of DC current I_E is

A bipolar transistor is operating in the active region with a collector current of 1 mA. Assuming that the $\beta$ of the transistor is 100 and the thermal voltage (V_T) is 25 mV, the transconductance (g_m) and the input resistance ($r_x$)the transistor in the common emitter configuration, are

For the BJT Q_L in the circuit shown below, $\beta = \infty$, $V_{BE_{on}} = 0.7, V_{CE_{sat}}$0.7V. The switch is initially closed. At time t = 0, the switch is opened. The time t at which Q₁ leaves the active region is

For a BJT the common base current gain $\alpha$ = 0.98 and the collector base junction reverse bias saturation current I_CO 0.6$\mu A$. This BJT is connected in the common emitter mode and operated in the active region with a base drive current I_B = 20XA. The collector current I_C for this mode of operation is

In the silicon BJT circuit shown below, assume that the emitter area of transistor Q1 is half that of transistor Q2.

The value of current I₀ is approximately