CS Free MCQ Bank

[ Option B ]

In digital electronics, different logic families vary in terms of speed, power consumption, and noise immunity. CMOS (Complementary Metal-Oxide-Semiconductor) is known for minimum power dissipation because it uses both PMOS and NMOS transistors in such a way that current flows only during switching, not in steady state.
In contrast, TTL (Transistor-Transistor Logic) and ECL (Emitter Coupled Logic) consume more power because current continuously flows through their circuits even when not switching.

[ Option B ]

JFET stands for Junction Field Effect Transistor. It is a unipolar device because its operation depends on only one type of charge carrier.

• In an N-channel JFET, current flows due to electrons only.
• In a P-channel JFET, current flows due to holes only.

Since only one type of carrier takes part in conduction, it is called a unipolar device.
A Bipolar Device is an electronic device in which both electrons and holes participate in current conduction. For example, a BJT (Bipolar Junction Transistor) is called bipolar because it uses both types of charge carriers.

[ Option D ]

Bipolar:

• RTL (Resistor-Transistor Logic)
• DTL (Diode-Transistor Logic) 
• TTL (Transistor-Transistor Logic) 
• ECL (Emitter-Coupled Logic) 
• IIL (Integrated Injection Logic)

Unipolar:

• NMOS (N-type Metal Oxide Semiconductor) 
• PMOS (P-type Metal Oxide Semiconductor) 
• CMOS (Complementary MOS)

Note:

Bipolar families use BJTs (Bipolar Junction Transistors), while unipolar families use MOSFETs (Metal-Oxide Semiconductor FETs) as switching devices.

[ Option D ]

FET (Field Effect Transistor) is widely used as a switching element in digital electronics. The most popular logic family using FETs is CMOS (Complementary Metal Oxide Semiconductor).