Chapter 7 Test 8

Question 1

A small air gap is left in the iron core amateur circuit to __________.

Answer 1

prevent the amateur from staying in a sealed position

Question 2

A(n) __________ is the number of locations within the valve in which the spool is placed to direct fluid through the valve.

Answer 2

position

Question 3

Voltage should be at least __________ % of a solenoid’s rated valve.

Answer 3

85

Question 4

Without the __________, excessive noise, wear, and heat buildup on the amateur faces.

Answer 4

shading coil

Question 5

__________ magnets are magnets that can retain their magnetism after a magnetizing force haas been removed.

Answer 5

Permanent

Question 6

__________ magnets are magnets that have extreme difficulty in retaining any magnetizing after the magnetizing force has been removed.

Answer 6

Temporary

Question 7

A burned out solenoid is normally evident by __________.

Answer 7

pungent odor cause by bunt insulation.

Question 8

A DC generator always has a(n) __________ armature and __________ field windings.

Answer 8

rotating a stationary

Question 9

The __________ is the relationship between the current in a conductor and the magnetic field existing around the conductor.

Answer 9

left hand generator rule

Question 10

The output voltage of a shunt-wound generator may be controlled by means of a(n) __________ connected in series with the shunt field.

Answer 10

rheostat

Question 11

The __________ theory of magnetism states that all substances are made up of an infinite number of molecular magnets.

Answer 11

molecular

Question 12

A(n) ___________ is an electric output device that converts electrical energy into a linear mechanical force.

Answer 12

solenoid

Question 13

The __________ is used to determine the direction of motion of a current-carrying conductor in a magnetic field.

Answer 13

electron flow motor rule

Question 14

__________ is unwanted current induced in tthe metal structure of a device.

Answer 14

Eddy Current

Question 15

A(n) ___________ is a single turn of conducting material mounted on the face of the magnetic laminate assembly or armature.

Answer 15

shading coil

Question 16

The mechanical life of most coils is improved by encapsulating them in a(n) ___________ or a glass-reinforced alkyd material.

Answer 16

epoxy resin

Question 17

__________ voltage is the minimum control voltage which causes the armature to start to move.

Answer 17

Pick-up

Question 18

__________ voltage is the voltage that exists when voltage is reduced sufficiently to allow the solenoid to open.

Answer 18

Drop-out

Question 19

Manufacturers provide letter or __________ codes to indicate the voltages available for a given solenoid.

Answer 19

number

Question 20

__________, two-way valves are common in refrigeration equipment.

Answer 20

Direct-acting

Question 21

DC series motors can develop __________ % of full-load torque upon starting.

Answer 21

up to 500

Question 22

A solenoid __________ when the voltage is excessive.

Answer 22

overheats

Question 23

__________ voltages may damage the insulation on the solenoid coil.

Answer 23

Transient

Question 24

No movement of the needle on an analog meter or infinite resistance on a(n) __________ set to measure resistance indicates the coil is open and defective.

Answer 24

DMM

Question 25

__________ valves are used as shutoff, check, or quick-exhaust valves.

Answer 25

Two-way

Question 26

A(n) ___________ circuit is a circuit in which current leaves its normal path and travels to the frame of the motor.

Answer 26

grounded

Question 27

A(n) __________ motor is used when high starting torque and constant speed are required.

Answer 27

DC compound

Question 28

A(n) __________ connects a brush to the external circuit of a DC motor.

Answer 28

pigtail

Question 29

The strength of an electromagnet can be increased by __________.

Answer 29

increasing the voltage
increasing the number of coils
inserting an iron core through the coil