Practice Test: Question Set - 05
1. The core of an electromagnet is said to be in saturation when:
- (A) The core is
permitted to move freely within the coil
- (B) An increase
in current through the coil causes no further increase in the mmf
- (C) Frequent
changes in the direction of current through the coil causes heating effects in
the core material
- (D) Changing the
polarity of the current in the coil changes the polarity of the magnetic field
around the core
2. Which one of the following phrases most accurately describes the nature of a pulsating dc voltage?
- (A) The voltage
remains at one polarity and at a steady level
- (B) The voltage
remains at one polarity but changes value periodically
- (C) The voltage
causes current to flow in two directions at the same time
- (D) The voltage
reverses polarity periodically
3. Which one of the following statements best applies to a series RLC circuit?
- (A) The voltage
waveform for each component always has the same amplitude and phase as the
applied voltage
- (B) The current
waveform for each component always has the same amplitude and phase as the
applied current
- (C) The sum of
the current is always less than the applied current
- (D) None of the
above
4. If a transistor operates at the middle of the load line, an increase in the current gain will move the Q point
- (A) Down
- (B) Up
- (C) Nowhere
- (D) Off the load
line
5. The total impedance of a series RLC circuit:
- (A) Is minimum
at the resonant frequency
- (B) Always
increases as the applied frequency increases
- (C) Always
decreases as the applied frequency increases
- (D) Is maximum
at the resonant frequency
6. A step-down transformer has turns ration of 5:1. If the primary voltage is 120 Vrms, what is the secondary voltage?
- (A) 12 V
- (B) 18 V
- (C) 24 V
- (D) 30 V
7. The total capacitance of a series capacitor circuit is:
- (A) Equal to the
sun of the individual capacitive-reactance values
- (B) Equal to the
sum of the individual capacitance values
- (C) Equal
to the source voltage divided by total current
- (D) Less than
the value of the smallest capacitor
8. Electron current is flowing through a conductor in a direction you might describe as straight into this page. What is the direction of the resulting magnetic field?
- (A) Clockwise
- (B) Counterclockwise
- (C) Out of this
page
- (D) Into this
page
9. What causes the depletion layer?
- (A) Doping
- (B) Recombination
- (C) Barrier
potential
- (D) Ions
10. A typical light switch in your home is a:
- (A) Knife
switch
- (B) Toggle
switch
- (C) Rotary
switch
- (D) Momentary
push button switch
11. For normal operation of the transistor, the collector diode has to be
- (A) Forward-biased
- (B) Reverse-biased
- (C) Non-conducting
- (D) Operating
in the breakdown region
12. When applying a square waveform to a capacitor, the circuit tends to:
- (A) Peak
the voltage and round off the current waveforms
- (B) Peak
the current and round off the voltage waveforms
- (C) Round
off both the voltage and current waveforms
- (D) Peak
both the voltage and current waveforms
13. A circuit has two different voltage sources that are connected in a series-aiding form. If the sources are rated at 6 V and 9 V, what is the total source voltage?
- (A) 15 V
- (B) 16 V
- (C) 7.5 V
- (D) 8 V
14. The graph of current gain versus collector current indicates that the current gain
- (A) Varies
enormously
- (B) Is
constant
- (C) Varies
slightly
- (D) Equals
the collector current divided by the base current
15. The total inductive reactance of a parallel inductor circuit is:
- (A) Equal
to the sum of the individual inductive-reactance values
- (B) Equal
to the sum of the individual inductance values
- (C) Equal
to the source voltage divided by total current
- (D) Less
than the inductance value of the smallest inductor
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