Electronic Test 5 Volume 1

1 A negatively charged body has
(A) excess of electrons
B. deficit of neutrons
C. excess of neutrons
D. deficit of electrons
2. For a bridge rectifier circuit, the output voltage is a
A. half-wave signal
(B) full-wave signal
C. bridge rectified-signal
D. square wave signal
3. The commutator pitch for a simplex lap winding is equal to
A. the number of poles of the machine
(B) 1
C. pole pairs
D. 2
4. The real working part of d.c machine is the
A commutator
(B) armature winding
C. field winding
D. stator
5. What is the barrier potential across each depletion layer?
A. 0
B. 1 V
C. 0.3 V
(D) 0.7 V
6. The purpose of load in an electric circuit us to
A. increase the circuit current
B. decrease the circuit current
(C). utilize electrical energy
D. minimize wasted energy
7. In order to get good integration, RC product should be at least ___ times than the time period of the input wave.
(A) 10
B. 50
C. 100
D. 1000
8. One would find a clamping circuit in
(A) television receivers
B. radio transmitters
C. receiving antennas
D. radio receivers
9. The most commonly used cell is
A. nickel-cadmium cell
B. nickel- iron cell
(C) lead-acid cell
D. fuel cell
10. The negative resistance characteristic of tetrode is due to
(A) secondary emission
B. plate being positive with respect to cathode
C. control grid being negative with respect to cathode
D. screen grid being negative with respect to cathode
11. A Shockley-diode is the sane as
A. an SCR
B. a triac
C. a diac
(D) a four-layer diode
12. Where does the input current to an inverting voltage amplifier (IVA) flow?
A. Through the load resistor
B. Into the ground
(C) Through the series resistor
D. Into the non-inverting input
13. The unit of transconductance is
A. ohms
(B) mhos
C. henry
D. darafs
14. Which of the following is used by a swamped amplifier?
(A) Negative feedback
B. Positive feedback
C. Regenerative feedback
D. An emitter ground
15. The disadvantage of a mechanical switch is that it
A. is operated mechanically
B. is costly
(C) has high inertia
D. has low inertia
16. The critical frequency of the collector bypass circuit ____ if the collector resistance decreases.
A. cannot be determined
(B) increases
C. decreases
D. stays the same
17. The maximum value of voltage breakdown by the zener mechanism is in the region to
A. 50 to 80 V
B. 100 to 200 V
C. above 200 V
(D) 5 to 8 V
18. The SI unit of reluctance is
A. N/Wb
(B) AT/Wb
C. AT/m
D. AT
19. Parasitic oscillations are unwanted oscillation of
A. magnetic origin
B. low frequency
C. high frequency
(D) very high frequency
20. A vacuum tube is normally operated in the temperature
saturation region to
(A) protect against filament aging
B. keep the tube envelope hot
C. disperse the space charge
D. keep the tube envelope cold
21. In a dc generator, armature reaction ______ pole tip.
A. weakens the flux at the trailing
B. strengthens the flux at the leading
(C) weakens the flux at the leading
D. strengthens the flux at the trailing
22. Dynamic impedance of parallel tuned circuit is
(A) L/CR
B. L/C
C. RL/C
D. R/L
23. Once a thyratron is fired, its control grid _______ over
plate current.
(A) losses all control
B. exercises rough control
C. exercises fine control
D. gains full control
24. Assume the valence electron is removed from copper atom.
The net charge of the atom becomes
A. 0
B. -1
(C) +1
D. +4
25. Negative feedback reduces the
A. feedback fraction
(B) distortion
C. error voltage
D. input offset voltage
26. ________ is a circuit with fixed emitter current.
(A) Emitter bias
B. Base bias
C. Transistor bias
D. Two-supply bias
27. Permanent magnets use _______ as the magnetic material.
A. soft steel
B. iron
C. nickel
(D) hardened steel
28. The control element in an SCR is
A. anode
(B) gate
C. cathode
D. anode supply
29. The Q-point for maximum unclipped output is at
the center of the
A. emitter voltage
B. collector voltage
C. dc load line
(D) ac load line
30. What kind of oscillator is found in an electronic
wristwatch?
A. Hartley
B. Clapp
C. Colpitts
(D) Quartz crystal