Bipolar Transistors as Switches

What is the primary advantage of using voltage control devices in digital control systems?

They are more expensive than current control devices
They require high control current
They require very low control current (correct)
They are less convenient to use than current control devices

What is the relationship between iD and VDS in many VGS conditions?

It is a constant resistance
It is a constant current
It is the I-V characteristics (correct)
It is a constant voltage

What is the region where the drain current differs by the gate-to-source voltage, and not by the drain-to-source voltage?

Cut-off region
Ohmic region
Linear region
Saturation region (correct)

What is the state of the power MOSFET when the gate-to-source voltage is lower than the VGS(th)?

Cut-off (C) Signup and view all the answers

What type of device is a power MOSFET?

Unipolar, majority carrier (C) Signup and view all the answers

What is the term for the minimum voltage required to turn on a MOSFET?

VGS(th) (B) Signup and view all the answers

What is a key problem in using bipolar transistors as switches?

Providing sufficient base drive current (C) Signup and view all the answers

What is the purpose of the resistor in the example light-switch circuit?

To provide enough base current to ensure the transistor is saturated (C) Signup and view all the answers

What is the typical operation of a transistor in digital circuits?

As a switch, with only 'on' and 'off' values (A) Signup and view all the answers

What is the purpose of varying IB in the experiment described in the procedure?

To measure the effect of base current on the transistor's operation (A) Signup and view all the answers

What is the mode of the oscilloscope set to in the procedure?

X-Y mode (B) Signup and view all the answers

What is the voltage division ratio set on Channel 1 of the oscilloscope in the procedure?

5V/Div (B) Signup and view all the answers

What is the condition for an N-type conducting channel to be induced in a MOSFET?

Gate voltage is positive and beyond a threshold value (D) Signup and view all the answers

What is the purpose of the integral body diode in a MOSFET?

To carry full current in the reverse direction (D) Signup and view all the answers

What is the relationship between the conduction resistance (RDS(ON)) and the drain-source voltage (VDS) of a high voltage MOSFET?

RDS(ON) α VDS^2.5 (B) Signup and view all the answers

What is the advantage of the positive temperature coefficient of RDS(ON) in MOSFETs?

It makes parallel operation of MOSFETs easy (C) Signup and view all the answers

What is the purpose of the trench gate technology in modern MOSFETs?

To lower the conduction resistance of the device (C) Signup and view all the answers

How are large MOSFETs typically fabricated?

By connecting multiple devices in parallel (C) Signup and view all the answers

What is the intrinsic standoff ratio (η) of a UJT?

The ratio of the variable resistance to the total resistance (B) Signup and view all the answers

What happens when the input voltage is greater than the drop across the diode plus the drop at the variable resistance R B1?

The device turns on and holes move from emitter to base (D) Signup and view all the answers

What is the region of operation characterized by a sudden increase in charge concentration in base1 region?

Negative resistance region (B) Signup and view all the answers

How many operating regions does a UJT have?

3 (C) Signup and view all the answers

What is the purpose of setting the oscilloscope to X-Y mode in the procedure?

To display the UJT characteristics (B) Signup and view all the answers

What is the value of VBB set in the procedure?

5 V (D) Signup and view all the answers

What can trigger a thyristor into conduction when the anode is positive?

A short positive gate current pulse (B) Signup and view all the answers

What is the minimum current required to maintain the conduction state of a thyristor?

Holding current (C) Signup and view all the answers

What happens to the forward breakover voltage as the gate current increases?

It decreases (B) Signup and view all the answers

What is the characteristic of a thyristor with a high gate current?

It behaves like a diode with the entire forward blocking region removed (D) Signup and view all the answers

What is the characteristic of a modern thyristor?

High voltage and high current ratings (C) Signup and view all the answers

What is the effect of a rise in junction temperature on a thyristor?

It turns on the device (A) Signup and view all the answers