Deck 1: Bipolar Junction Transistors BJTS

Question 1

Which of the following condition is true for cut-off mode?

A)the collector current is zero
B)the collector current is proportional to the base current
C)the base current is non zero
D)all of the mentioned

Answer 1

the collector current is zero

Question 2

Which of the following is true for the cut- off region in an npn transistor?

A)potential difference between the emitter and the base is smaller than 0.5v
B)potential difference between the emitter and the base is smaller than 0.4v
C)the collector current increases with the increase in the base current
D)the collector current is always zero and the base current is always non zero

Answer 2

potential difference between the emitter and the base is smaller than 0.4v

Question 3

Which of the following is true for a typical active region of an npn transistor?

A)the potential difference between the emitter and the collector is less than 0.5 v
B)the potential difference between the emitter and the collector is less than 0.4 v
C)the potential difference between the emitter and the collector is less than 0.3 v
D)the potential difference between the emitter and the collector is less than 0.2 v

Answer 3

the potential difference between the emitter and the collector is less than 0.3 v

Question 4

Which of the following is true for the active region of an npn transistor?

A)the collector current is directly proportional to the base current
B)the potential difference between the emitter and the collector is less than 0.4 v
C)all of the mentioned
D)none of the mentioned

Question 5

Which of the following is true for a npn transistor in the saturation region?

A)the potential difference between the collector and the base is approximately 0.2v
B)the potential difference between the collector and the base is approximately 0.3v
C)the potential difference between the collector and the base is approximately 0.4v
D)the potential difference between the collector and the base is approximately 0.5v

Question 6

The potential difference between the base and the collector Vcb in a pnp transistor in saturation region is                  

A)-0.2 v
B)-0.5v
C)0.2 v
D)0.5 v

Question 7

For a pnp transistor in the active region the value of Vce (potential difference between the collector and the base) is

A)less than 0.3v
B)less than 3v
C)greater than 0.3v
D)greater than 3v

Question 8

Which of the following is true for a pnp transistor in active region?

A)cb junction is reversed bias and the eb junction is forward bias
B)cb junction is forward bias and the eb junction is forward bias
C)cb junction is forward bias and the eb junction is reverse bias
D)cb junction is reversed bias and the eb junction is reverse bias

Question 9

Which of the following is true for a pnp transistor in saturation region?

A)cb junction is reversed bias and the eb junction is forward bias
B)cb junction is forward bias and the eb junction is forward bias
C)cb junction is forward bias and the eb junction is reverse bias
D)cb junction is reversed bias and the eb junction is reverse bias

Question 10

For the circuit shown, find the quiescent point.

A)none of the below
B)(4v, 10ma)
C)(10v, 3ma)
D)(3ma, 10v)

Question 11

What is the DC characteristic used to prove that the transistor is indeed biased in saturation mode?

A)ic = ?ib
B)ic > ?ib
C)ic >> ?ib
D)ic < ?ib

Question 12

The feature of an approximate model of a transistor is

A)it helps in quicker analysis
B)it provides individual analysis for different configurations
C)it helps in dc analysis
D)ac analysis is not possible

Question 13

005mmhos, hre=0. Find the output impedance if the lad resistance is 5k?.

A)5k?
B)4k?
C)20k?
D)15k?

Question 14

A transistor has hie =2k?, hoe=25µmhos and hfe=60 with an unbypassed emitter resistor Re=1k?. What will be the input resistance and output resistance?

A)90k? and 50k? respectively
B)33k? and 45k? respectively
C)6k? and 40k? respectively
D)63k? and 40k? respectively

Question 15

A transistor has hie =1K? and hfe=60 with an bypassed emitter resistor Re=1k?. What will be the input resistance and output resistance?

A)90k? and 50k? respectively
B)33k? and 45k? respectively
C)6k? and 40k? respectively
D)63k? and 40k? respectively

Question 16

In the given circuit, find the equivalent resistance between A and B nodes.

A)100k?
B)50k?
C)40k?
D)60k?

Question 17

Which of the following acts as a buffer?

A)cc amplifier
B)ce amplifier
C)cb amplifier
D)cascaded amplifier

Question 18

Which of the following is true?

A)cc amplifier has a large current gain
B)ce amplifier has a large current gain
C)cb amplifier has low voltage gain
D)cc amplifier has low current gain

Question 19

In CB configuration, the value of ?=0.98A. A voltage drop of 4.9V is obtained across the resistor of 5K? when connected in collector circuit. Find the base current.

A)0.01ma
B)0.07ma
C)0.02ma
D)0.05ma

Question 20

Which of the following is the correct relationship between base and emitter current of a BJT?

A)ib = ? ie
B)ib = ie
C)ib = (? + 1) ie
D)ie = (? + 1) ib

Question 21

For best operation of a BJT, which region must the operating point be set at?

A)active region
B)cutoff region
C)saturation region
D)reverse active region

Question 22

From the given circuit, using a silicon transistor, what is the value of IBQ?

A)47.08 ma
B)47.08 ua
C)50 ua
D)0 ma

Question 23

From the given circuit, using a silicon BJT, what is the value of VCEQ?

A)7 v
B)0.7 v
C)6.83 v
D)7.17 v

Question 24

From the given circuit, using a silicon BJT, what is the value of VBC?

A)6.13 v
B)-6.13 v
C)7 v
D)-7 v

Question 25

From the given circuit, using silicon BJT, what is the value of the saturation collector current?

A)5 ma
B)5.36 ma
C)5.45 ma
D)10.9 ma