Midterm

Question 1

Copper is a good conductor.

True

False

 

Question 2

Doping is a process of adding impurity atoms to an intrinsic crystal to alter its electrical conductivity.

True

False

 

Question 3

You can quickly check the condition of a diode with an ohmmeter on a high resistance range. 

True

False

 

Question 4

The letter Q is an abbreviation for quiescent, which represents the AC signal is operating between cut-off and saturation points of the transistor.

True

False

 

Question 5

The half-wave rectifier has a diode in parallel with a load resistor. 

True

False

 

Question 6

In an NPN transistor, the emitter and collector are both n-type materials. 

True

False

 

Question 7

The dc beta is also known as the current gain because a small base current controls a much larger collector current. 

True

False

 

Question 8

The load line is a visual summary of all the possible transistor operating points.

True

False

 

Question 9

With the switch in the position as shown in Figure 1 below, the LED is on. 

Figure 1

True

False

 

Question 10

A transistor can be tested using an ohmmeter to check back and front resistances of emitter-base, collector-base, and collector-emitter. 

True

False

 

Question 11

Hard saturation refers to any design that makes the saturation current gain approximately:

		1
		10
		100
		1000

 

Question 12

While testing a transistor with an ohmmeter, a high reverse/forward resistance ratio for the emitter-base and base-collector junctions indicates

		this transistor is good.
		this transistor is open and should be replaced.
		this transistor is shorted and should be replaced.
		this transistor is a small-signal amplifier.

 

Question 13

A major advantage of an optocoupler is the:

		electrical isolation between input and output circuits.
		electrical connection between input and output circuits.
		higher gain.
		low cost of manufacturing the device.

 

Question 14

With normal circuit operation, Vout in Figure 2 is ________.

Figure 2

		Approximately 0V
		115 Vac
		20 V
		10 V DC

 

Question 15

If the 115 V ac is removed from the circuit shown in Figure 2, what would be measured at Vout?

Figure 2

		approximately 0 V
		115 V
		20 V
		10 V

 

Question 16

What type transistor connection is shown in Figure 3 below?

Figure 3

		common emitter
		common collector
		common base
		emitter follower

 

Question 17

What is the device that increases a transistor's power rating by reducing the internal heat faster?

		heater wire
		chassis
		grommet
		heat sink

 

Question 18

Another name for diode offset voltage is:

		barrier potential
		ripple voltage
		surge voltage
		filtered voltage

 

Question 19

The second approximation of a silicon diode is basically the:

		the diode appears as a switch in series with a barrier potential of 0.7 V
		the diode appears as a switch in parallel with a barrier potential of 0.7 V
		the diode appears as a barrier potential of 0.4 V
		the diode appears as a short circuit

 

Question 20

What is the most popular and useful semiconductor material?

		silver
		Copper
		Aluminum
		Silicon

 

Question 21

Refer to Figure 4 below.

Figure 4

A. What is the Peak secondary voltage?

B. What is the peak-to-peak voltage at the filter point considering non-ideal diode?   

Question 22

For the CE circuit shown in Figure 5 below, draw the dc load line and mark the dc working point on it.  Assume Beta=100 and neglect VBE.

Figure 5