Analog Electronics - Study Mode

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[#116] A full wave rectifier with a centre tapped transformer supplies dc current of 100 mA to a load resistance of 20Ω. The secondary resistance of transformer is 1Ω. Each diode has a forward resistance of 0.5Ω. What are rms values of signal voltage across each half of the secondary as well as dc power supplied to the load?

(A) 2.39 V and 0.2 Watt

(B) 23.9 V and 2 Watts

(C) 0.239 V and 20 Watts

(D) 2.39 V and 2 Watts

Correct Answer

(A) 2.39 V and 0.2 Watt

[#117] Two transistors have the same value of α but different gain bandwidth products. One of them is a germanium transistor and the other is a silicon transistor. Both the transistors have similar geometries and base width. The transistor with lower GB product.

(A) Is the germanium

(B) Is the silicon

(C) Both are same

(D) Cannot be identified unless more information is available

Correct Answer

(B) Is the silicon

[#118] A transistor RC coupled amplifier is designed for a voltage and band gain of 20. But a measurement at a particular frequency shows the gain to be only 14. What is the likely phase shift at this frequency?

(A) 180°

(B) 135°

(C) 90°

(D) 45°

Correct Answer

(B) 135°

[#119] The Wien bridge oscillator is

(A) a free running oscillator

(B) a square wave generator

(C) a stable sine wave generator

(D) also called cosine oscillator

Correct Answer

(C) a stable sine wave generator

[#120] In a CMOS CS amplifier, the active load is obtained by connecting a

(A) p channel current mirror circuit

(B) n channel transistor

(C) p channel transistor

(D) BJT current mirror

Correct Answer

(A) p channel current mirror circuit