Electronics (ECE) - MCQ Practice Questions

In a BJT, if the base-emitter junction is forward biased and the base-collector junction is also forward biased, the transistor is operating in which region?

A BJT has β = 100 and early voltage VA = 80 V. If IC = 2 mA and VCE = 10 V, what is the small signal output resistance ro?

In a MOSFET, the transconductance gm depends on which parameters in saturation region?

A tunnel diode exhibits negative differential resistance. At what operating point is the dynamic resistance most negative?

In a photodiode, the photocurrent is primarily determined by which parameter?

A light-emitting diode (LED) has a bandgap of 2.5 eV. What is the approximate wavelength of emitted light?

In a JFET, as the reverse bias voltage on the gate-source junction increases, what happens to the channel width?

A CMOS logic gate has static power dissipation. Which phenomenon is primarily responsible for this in 2024 technology nodes?

A thyristor (SCR) is triggered into conduction. To turn it off, which method is most commonly used in AC circuits?

A DIAC is used in a light dimmer circuit. What is its primary characteristic?

In a BJT common-emitter amplifier with emitter bypass capacitor, what is the primary effect on voltage gain?

A MESFET (Metal-Semiconductor FET) differs from a JFET primarily in which aspect?

In a p-channel MOSFET, if VGS = -8 V and VT = -2 V, what is the gate-source overdrive voltage?

A power MOSFET has RDS(on) = 0.5 Ω and carries 20 A. What is the approximate conduction power loss?

In a heterostructure bipolar transistor (HBT), the wide bandgap material in the emitter provides which advantage?

Which semiconductor material has the highest electron mobility among common choices?

A device operates with reverse saturation current IS = 10^-14 A at 25°C. If temperature increases to 75°C, by approximately what factor does IS increase?

In a silicon p-n junction diode at room temperature (T = 300K), the thermal voltage (VT) is approximately:

A germanium BJT has a base-emitter voltage VBE = 0.3 V in forward bias. Compared to a silicon BJT with VBE = 0.7 V, which statement is correct?

In an n-channel depletion-mode MOSFET with Vto = -3 V, if VGS = 0 V, the device is in which region?