Quiz on Module 1

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

• IB = β IE

• IB = IE

• IB = (β + 1) IE

• IE = (β + 1) IB

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

• Active region

• Cutoff region

• Saturation region

• Reverse active region

BJT is biased to _________

• Work as a switch

• Prevent thermal runaway

• Increase DC collector current

• Operate it in the saturation region

The biasing circuit that gives best stability to Q point is

• base resistance biasing

• feedback resistor biasing

• potential divider biasing

• emitter resistor biasing

The potential divider biasing is used in amplifiers to

• limit the input ac signal going to the base

• reduce dc base current

• reduce the cost of the circuit by limiting the number of resistors

• make the operating point almost independent of β

A transistor with ß = 120 is biased to operate at a dc collector current of 1.2 mA. Find the value of gm.

• 12mA/V

• 24 mA/V

• 36 mA/V

• 48 mA/V

A transistor operating with nominal gm of 60 mA/V has a ß that ranges from 50 to 200. Also, the bias circuit, being less than ideal, allows a 20% variation in Ic. What is the smallest value found of the resistance looking into the base?

• 347 ohm

• 694 ohm

• 1041 ohm

• 1388 ohm

A designer wishes to create a BJT amplifier with a gm of 50 mA/V and a base input resistance of 2000 O or more. What is the minimum ß he can tolerate for the transistor used?

• 100

• 150

• 200

• 250

The SI units of transconductance is

• Ampere/ volt

• Volt/ ampere

• Ohm

• Siemens

Consider the following circuit. Process transconductance parameter = 0.50 mA/V2, W/L=1, Threshold voltage = 3V, VDD = 20V. Find the operating point of circuit.

• 20V, 25mA

• 13V, 22mA

• 12.72V, 23.61mA

• 20V, 23.61mA