BJT GROB

Question 1

1. Which transistor region is very thin
   and lightly doped?
   a. the emitter region.
   b. the collector region.
   c. the anode region.
   d. the base region.

Answer 1

d. the base region.

Question 2

2. Which region in a transistor is the
   most heavily doped?
   a. the emitter region.
   b. the collector region.
   c. the gate region.
   d. the base region.

Answer 2

a. the emitter region.

Question 3

3. In a transistor, which is the largest of
   all the doped regions?
   a. the emitter region.
   b. the collector region.
   c. the gate region.
   d. the base region.

Answer 3

b. the collector region.

Question 4

4. For a transistor to function as an
   amplifi er,
   a. both the EB and CB junctions
   must be forward-biased.
   b. both the EB and CB junctions
   must be reverse-biased.
   c. the EB junction must be forward-
   biased and the CB junction must be reverse-biased.
   d. the CB junction must be forward-
   biased and the EB junction must be reverse-biased.

Answer 4

c. the EB junction must be forward-
biased and the CB junction must be reverse-biased.

Question 5

5. For a typical transistor, which
   two currents are nearly the
   same?
   a. IB and IE.
   b. IB and IC.
   c. IC and IE.
   d. none of the above.

Answer 5

c. IC and IE.

Question 6

6. In what operating region does the
   collector of a transistor act like a
   current source?
   a. the active region.
   b. the saturation region.
   c. the cutoff region.
   d. the breakdown region.

Answer 6

a. the active region.

Question 7

7. A transistor operating in the active
   region has a base current, IB, of
   20 microA. If bDC = 250, how much is
   the collector current, IC?
   a. 50 mA.
   b. 5 mA.
   c. 12.5 mA.
   d. 80 A.

Answer 7

b. 5 mA.

Question 8

8. Which of the following biasing
   techniques produces the most
   unstable Q point?
   a. voltage divider bias.
   b. emitter bias.
   c. collector bias.
   d. base bias.

Answer 8

d. base bias.

Question 9

9. When the collector current in a
   transistor is zero, the transistor is
   a. cut off .
   b. saturated.
   c. operating in the breakdown region.
   d. either b or c.

Answer 9

a. cut off .

Question 10

10. When a transistor is in saturation,
    a. VCE = VCC.
    b. IC = 0 A.
    c. VCE = 0 V.
    d. VCE = 1⁄2VCC.

Answer 10

c. VCE = 0 V.

Question 11

11. Emitter bias with two power supplies
    provides a
    a. very unstable Q point.
    b. very stable Q point.
    c. large base voltage.
    d. none of the above.

Answer 11

b. very stable Q point.

Question 12

12. The aDC of a transistor equals
    a. IC/IE.
    b. IB/IC.
    c. IE/IC.
    d. IC/IB.

Answer 12

a. IC/IE

Question 13

13. For a transistor operating in the
    active region,
    a. IC = BDC x IB.
    b. VCC has little or no effect on the value of IC.
    c. IC is controlled solely by VCC.
    d. both a and b.

Answer 13

d. both a and b.

Question 14

14. In a transistor amplifi er, what
    happens to the collector voltage,
    VC, when the collector current, IC,
    increases?
    a. VC increases.
    b. VC stays the same.
    c. VC decreases.
    d. It cannot be determined.

Answer 14

c. VC decreases.

Question 15

15. With voltage divider bias, how much is
    the collector-emitter voltage, VCE,
    when the transistor is cut off ?
    a. VCE = 1⁄2 VCC.
    b. VCE = VCC.
    c. VCE = 0 V.
    d. none of the above.

Answer 15

b. VCE = VCC.

Question 16

16. On the schematic symbol of a pnp
    transistor,
    a. the arrow points out on the
    emitter lead.
    b. the arrow points out on the
    collector lead.
    c. the arrow points in on the base lead.
    d. the arrow points in on the emitter lead

Answer 16

d. the arrow points in on the emitter lead

Question 17

17. What is the bDC of a transistor whose
    aDC is 0.996?
    a. 249.
    b. 100.
    c. approximately 1.
    d. It cannot be determined.

Answer 17

a. 249.

Question 18

18. In a transistor, which current is the
    largest?
    a. IC.
    b. IB.
    c. IE.
    d. ID.

Answer 18

c. IE.

Question 19

19. A bipolar junction transistor has
    a. only one p-n junction.
    b. three p-n junctions.
    c. no p-n junctions.
    d. two p-n junctions.

Answer 19

d. two p-n junctions.

Question 20

20. The endpoints of a DC load line are
    labeled
    a. ICQ and VCEQ.
    b. IC(sat) and VCE(off ).
    c. IC(off ) and VCE(sat).
    d. none of the above.

Answer 20

b. IC(sat) and VCE(off ).