Automotive Electrical and Electronic Systems Classroom Manual Fifth Edition Update by John F. Kershaw

www.TechnicalBooksPDF.com
70 Chapter Four
Review Questions
1. Which of the following can store energy in
the form of an electromagnetic charge?
a. Thermocouple
b. Induction coil
c. Potentiometer
d. Capacitor
2. Current flows through a heated thermocouple
because of the two-way flow of
a. Electrons between dissimilar materials
b. The blockage of free electrons between
the metals
c. The one-way transfer of free electrons
between the metals
d. Random electron flow
3. Which of the following forms of generating
electricity is not widely used in an
automobile?
a. Heat
b. Pressure
c. Chemistry
d. Magnetism
4. The lines of force of a magnet are called
a. Flux lines
b. Magnetic polarity
c. Magnetic lines
d. Flux density
5. A material through which magnetic force
can easily flow has a high
a. Reluctance
b. Permeability
c. Capacitance
d. Magnetic attraction
6. The left-hand rule says that if you grasp a
conductor in your left hand with your thumb
pointing in the direction of the electron ( to
+) flow,
a. Your fingers will point in the direction of
the magnetic flux lines.
b. Your fingers will point in the opposite
direction of the magnetic flux lines.
c. Your fingers will point at right angles to
the magnetic flux lines.
d. Your fingers will point at a 45-degree
angle to the magnetic flux lines.
7. The left-hand rule is useful to determine
a. The direction of current flow
b. The length of the magnetic flux lines
c. The strength of the magnetic field
d. Flux density
8. When two parallel conductors carry
electrical current in opposite directions,
their magnetic fields will
a. Force them apart
b. Pull them together
c. Cancel each other out
d. Rotate around the conductors in the
same direction
9. The motor principle of changing electrical
energy into mechanical energy requires
a. Two semiconductors carrying current in
opposite directions
b. Two semiconductors carrying current in
the same direction
c. Two conductors carrying current in
opposite directions
d. Two conductors carrying current in the
same direction
10. Which of the following will not increase
induced voltage?
a. Increasing the strength of the magnetic
field
b. Increasing the number of conductors
cutting flux lines
c. Increasing the speed of the relative
motion between the conductor and the
flux lines
d. Increasing the angle between the flux lines
and the conductor beyond 90 degrees
11. The _________ in an automobile DC
generator rectifies AC to DC.
a. Armature
b. Commutator
c. Field coil
d. Loop conductor
12. In an ignition coil, low-voltage primary
current induces a very high secondary
voltage because of
a. The different number of wire turns in the
two windings.
b. An equal number of turns in the two
windings
c. The constant current flow through the
primary winding
d. The bigger wire in the secondary winding
13. To reduce EMI, manufacturers have done all
of the following except:
a. Using low resistance in electrical systems
b. Installing metal shielding in components
c. Increasing the use of ground straps
d. Using capacitors and choke coils