Analog Electronics - Study Mode

Show All Answers

[#281] A common emitter transistor amplifier has a collector load of 10 kΩ. If its h fe = 100 and h ie = 2 kΩ (h re ≈ h oe ≈ 0), the voltage amplification of the amplifier is nearly equal to

(A) 500

(B) 200

(C) 100

(D) 50

Correct Answer

(A) 500

[#282] When the gate-to-source voltage (V GS ) of a MOSFET with threshold voltage of 400 mV, working in saturation is 900 mV, the drain current is observed to be 1 mA. Neglecting the channel length modulation effect and assuming that the MOSFET is operating at saturation, the drain current for an applied V GS of 1400 mV is

(A) 0.5 mA

(B) 2.0 mA

(C) 3.5 mA

(D) 4.0 mA

Correct Answer

(D) 4.0 mA

[#283] Asource follower using an FET usually has a voltage gain which is

(A) Greater than +100

(B) Slightly less than unity but positive

(C) Exactly unity but negative

(D) About -10

Correct Answer

(A) Greater than +100

[#284] Three identical amplifiers with each one having a voltage gain of 50,input resistance of 1KΩ & output resistance of 250, are cascaded. The open circuit voltage gain of combined amplifier is

(A) 49dB

(B) 51dB

(C) 98dB

(D) 102dB

Correct Answer

(C) 98dB

[#285] A dc power supply has no-load voltage of 30v,and a full-load voltage of 25v at full-load current of 1A.Its output resistance & load regulation ,respectively are

(A) 5 Ω & 20 %

(B) 25 Ω & 20 %

(C) 5 Ω & 16.7 %

(D) 25 Ω & 16.7 %

Correct Answer

(B) 25 Ω & 20 %