Analog Electronics - Study Mode

Show All Answers

[#111] A bleeder resistor is used in a D.C power supply because it

(A) Keeps the supply OFF

(B) Keeps the supply ON

(C) Improves filtering action

(D) Improves voltage regulation

Correct Answer

(D) Improves voltage regulation

[#112] In the following astable multivibrator circuit, which properties of V 0 (t) depend on R 2 ?

(A) Only the frequency

(B) Only the amplitude

(C) Both the amplitude and the frequency

(D) Neither the amplitude nor the frequency

Correct Answer

(A) Only the frequency

[#113] In a half-wave rectifier, if an a.c. supply is 60 Hz, then what is the a.c. ripple at output?

(A) 30 Hz

(B) 60 Hz

(C) 120 Hz

(D) 15 Hz

Correct Answer

(B) 60 Hz

[#114] Consider an ideal long channel nMOSFET (enhancement-mode) with gate length 10 µm and width 100 µm. The product of electron mobility (µ n ) and oxide capacitance per unit are (C ox ) is µ n C ox = 1 mA/V 2 . The threshold voltage of the transistor is 1 V. For a gate-to-source voltage V GS = [2 - sin(2t)] V and drain-to-source voltage V DS = 1 V (substrate connected to the source), the maximum value of the drain-to-source current is . . . . . . . .

(A) 40 mA

(B) 20 mA

(C) 15 mA

(D) 5 mA

Correct Answer

(C) 15 mA

[#115] An n-channel depletion MOSFET has following two points on its I D - V GS curve: (i) V GS = 0 at I D = 12 mA and (ii) V GS = -6 volts at Z 0 = ∞ Which of the following Q-points will give the highest transconductance gain for small signals?

(A) V GS = -6 volts

(B) V GS = -3 volts

(C) V GS = 0 volts

(D) V GS = 3 volts

Correct Answer

(D) V GS = 3 volts