# GATE Questions & Answers of Characteristics of Diodes, BJT, MOSFET

## What is the Weightage of Characteristics of Diodes, BJT, MOSFET in GATE Exam?

Total 17 Questions have been asked from Characteristics of Diodes, BJT, MOSFET topic of Analog and Digital Electronics subject in previous GATE papers. Average marks 1.65.

In the circuit shown in the figure, the bipolar junction transistor (BJT) has a current gain $B=100$. The base-emitter voltage drop is a constant, $V_{BE}=0.7V.$ The value of the Thevenin equivalent resistance $R_{Th}$ (in $\Omega$) as shown in the figure is ______ (up to 2 decimal places).

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The circuit shown in the figure uses matched transistors with a thermal voltage VT = 25 mV. The base currents of the transistors are negligible. The value of the resistance R in $k\;\Omega$ that is required to provide 1 µA bias current for the differential amplifier block shown is ___________ . (Give the answer up to one decimal place.)

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For the circuit shown in the figure below, it is given that $V_{CE}=\frac{V_{CC}}V$. The transistor has $\beta=29$ and VBE=0.7 V when the B-E junction is forward biased

For this circuit, the value of $\frac{R_B}R$ is

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A transistor circuit is given below. The Zener diode breakdown voltage is 5.3 V as shown. Take base to emitter voltage drop to be 0.6 V. The value of the current gain β is _________.

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In the given circuit, the silicon transistor has and $a$ collector voltage Then the ratio of ${R}_{B}$ and ${R}_{C}$ is _______.

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The sinusoidal ac source in the figure has an rms value of $\frac{20}{\sqrt{2}}$  V. Considering all possible values of RL, the minimum value of RS in Ω to avoid burnout of the Zener diode is _________.

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Assuming the diodes to be ideal in the figure, for the output to be clipped, the input voltage vi must be outside the range

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A 10 kHz even-symmetric square wave is passed through a bandpass filter with centre frequency at 30 kHz and 3 dB passband of 6 kHz. The filter output is

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In the circuit shown below, the knee current of the ideal Zener diode is 10 mA. To maintain 5 V across RL, the minimum value of RL in $\Omega$ and the minimum power rating of the Zener diode in mW respectively are

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A voltage $1000\mathrm{sin}\omega t$ Volts is applied across YZ. Assuming ideal diodes, the voltage measured across WX in Volts is

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The i-v characteristics of the diode in the circuit given below are

The current in the circuit is

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The transistor used in the circuit shown below has a β of 30 and ICBO  is negligible

If the forward voltage drop of diode is 0.7V, then the current through collector will be

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A clipper circuit is shown below.

Assuming forward voltage drops of the diodes to be 0.7 V, the input-output transfer characteristics of the circuit is

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Figure shows a composite switch consisting of a power transistor (BJT) in series with a diode. Assuming that the transistor switch and the diode are ideal, the I-V characteristic of the composite switch is

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The equivalent circuits of a diode, during forward biased and reverse biased conditions, are shown in the figure.

If such a diode is used in clipper circuit of figure given above, the output voltage V0 of the circuit will be(A)(A)

 (A) (B) (C) (D)

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Two perfectly matched silicon transistor are connected as shown in the figure. Assuming the β of the transistors to be very high and the forward voltage drop in diodes to be 0.7 V, the value of current I is

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In the voltage doubler circuit shown in the figure, the switch ‘S ’ is closed at t = 0. Assuming diodes D1 and D2 to be ideal, load resistance to be infinite and initial
capacitor voltages to be zero. The steady state voltage across capacitors C1 and C2 will be