Two Marks Questions with Answers

Two Marks Questions with Answers

Q. 1 Draw the hybrid small signal model of common base configuration. (Refer Fig. 6.3.4)

AU : Dec.-02, Dec.-05, Dec.-06

Q. 2 What are hybrid parameters ?

(Refer section 6.2)

Q. 3 Draw the low frequency hybrid model of BJT in common emitter configuration.

(Refer Fig. 6.3.4)

Q. 4 Define the hle and hfe for a common emitter transistor configuration.

(Refer section 6.3.2)

Q. 5 Draw the hybrid model of a CE transistor.

(Refer section 6.3.2)

Q. 6 What are the steps used for small signal analysis of BJT ?

(Refer section 6.5)

Q. 7 Give the current gain expression for a common emitter transistor configuration.

Q. 8 Define the four h-parameters.

(Refer section 6.2)

Q. 9 State Miller’s theorem.

AU : ECE : May-04, 08, 12, Dec.-06, 07, 16

Ans. : Miller's theorem states that, if Z is the impedance connected between two nodes, node 1 and node 2, it can be replaced by two separate impedances Z1 andZ2; where Z1 is connected between node 1 and ground and Z2 is connected between node 2 and ground. The V; and Vo are the voltages at the node 1 and node 2 respectively. The values of Z1 andZ2 can be derived from the ratio of Vo and V; (Vo / V;), denoted as K. Thus it is not necessary to know the values of V; and Vo to calculate the values of Z1 and Z 2.

The values of impedances Z1 andZ2 are given as

Z₁ = Z / 1 – K and Z₂ = Z. K / K - 1

Q.10 Define the uarious h-parameters for a common emitter transistor.

(Refer section 6.3.2)

Q.11 What do you mean by faithful amplification ?

Ans. : During the process of raising the strength of the input signal if the shape of the output voltage is exactly same as that of the input signal, the amplification is called faithful amplification.

Q.12 State the advantages of using h-parameters for analyzing transistor amplifiers.

(Refer section 6.3.1)

Q.13 Give the voltage gain for CE configuration including source resistance.

Q.14 Draw general frequency response curve of an amplifier. AU : ECE : Dec.-07

 (Refer Fig. 6.9.1 (b))

Q.15 What is the significance of octaves and decades in frequency response ?

AU : ECE : Dec.-06

(Refer section 6.9)

Q.16 What is bandwidth of an amplifier ?

AU : May-07, Dec.-08, 09, May-09

Ans. : The bandwidth of the amplifier is defined as the difference between the lower cut-off frequency and the upper cut-off frequency.

B_W = f₂ - f₁

Q.17 What is roll-off ?

(Refer section 6.9) 

Q.18 What do you mean by half-power frequencies ?

(Refer section 6.9)

Q.19 State the effect of coupling and bypass capacitors on the frequency response of amplifier.

(Refer section 6.9.1)

Q.20 State the effect of internal transistor capacitances on the frequency response of amplifier.

(Refer section 6.9.1.3)

Q.21 Define the four h-parameters.

(Refer section 6.3.2)

Q.22 Draw the hybrid model of BJT in CE configuration.

(Refer section 6.3.3)

Q.23 What is the need of coupling capacitors in amplifier design? AU : Dec.-15

(Refer section 6.1.1)

Q.24 Draw the small signal model of BJT device.

[Refer Fig. 6.4.2]

Q.25 Draw the hybrid small signal model of CB configuration.

[Refer Fig. 6.3.4]

Q.26 State the phase relationships between input/output currents and between input/output voltages of uarious transistor configurations.

(Refer section 6.1.4)