Magneto

Question 1

The magnetic circuit of a magneto consists of a permanent multi-pole rotating magnet. The core is made of?

Answer 1

Soft iron

Question 2

How is the strength of a magneto magnet checked?

Answer 2

Hold the points open and check the output of the primary coil with an AC ammeter while operating the magnito at a specified speed

Question 3

The E gap angle is usually defined as a number of degrees between the neutral position of the rotating magnet and the position where?

Answer 3

Where the contact points open.

Question 4

The greatest density of flux lines in the magnetic circuit of a rotating magnet type magneto occurs when the magnet is in what position?

Answer 4

full alignment with the field shoe faces

Question 5

Magneto breaker point opening relative to the position of the rotating magnet and a distributor rotor (internal timing) can be set most accurately during?

Answer 5

During assembly of the magnito before installation on the engine

Question 6

Why are high tension Ignition cables frequently routed from the distributors to the spark plugs in flexible metallic conduits?

Answer 6

To reduce the effect of high frequency electromagnetic waves emanated during operation

Question 7

What will be the results of increasing the gap of the breaker points in a magneto?

Answer 7

Advance the spark and decrease the intensity

Question 8

What is the purpose of a safety gap in some magnetos?

Answer 8

To discharge the secondary coils voltage if an open circuit occurs in the secondary circuit

Question 9

When timing a magneto internally, the alignment of the timing marks indicates that the?

Answer 9

Magnets are in the E gap position

Question 10

When internally timing a magneto, the breaker points begin to open when the rotating magnet is?

Answer 10

A few degrees past the neutral position

Question 11

Magneto timing drift is caused by erosion of the breaker points and?

Answer 11

wear of the cam followers

Question 12

What is the electrical location of the primary capacitor in a high tension magneto?

Answer 12

In parallel with the breaker points

Question 13

In a high tension ignition system, the current in the magneto secondary winding is induced when?

Answer 13

Induced when the primary circuit is interrupted

Question 14

When a “shower of sparks” ignition system is activated at an engine start, the spark plug fires?

Answer 14

Only while both the retard and advance breaker points are open

Question 15

What is the radial location of the two north poles of a four pole rotating magnet in a high tension magneto?

Answer 15

180 degrees apart

Question 16

Magneto shoe poles are usually made of?

Answer 16

Laminations of high grade soft iron

Question 17

Capacitance after firing in most modern spark plugs is reduced by the use of?

Answer 17

A built in resistor in each plug

Question 18

What components make up the magnetic system of a magneto?

Answer 18

Rotating magnet, the pole shoes, the pole shoe extensions, and the coil core

Question 19

In an aircraft ignition system, one of the functions of the capacitor is to?

Answer 19

Facilitate a more rapid collapse of the magnetic field in the primary coil

Question 20

When will the voltage in the secondary winding of a magneto, installed on a normally operating engine, be at its highest value?

Answer 20

just prior to spark plug firing

Question 21

When the switch is off in a battery ignition system, the primary circuit is?

Answer 21

opened

Question 22

As an aircraft engine speed is increased, the voltage induced in the primary coil of the magneto?

Answer 22

increases

Question 23

When internally timing and magneto, the breaker points begin to open when?

Answer 23

The magnet polls are a few degrees beyond the neutral position

Question 24

The purpose of a safety gap in a magneto is to?

Answer 24

protect the high voltage windings from damage

Question 25

A defective primary capacitor in a magneto is indicated by?

Answer 25

burned and pitted breaker points

Question 26

How many secondary coils are required in a low tension Ignition system on an 18 cylinder engine?

Answer 26

36

Question 27

A magnito ignition switch is connected?

Answer 27

Parallel to the breaker points

Question 28

The spark is produced in a magnito ignition system where the breaker points are?

Answer 28

Beginning to open

Question 29

Shielding is used on spark plug and ignition wires to prevent?

Answer 29

Prevent interference with radio reception

Question 30

What is the purpose of using an impulse coupling with a magneto?

Answer 30

To produce a momentary high rotational speed of the magneto

Question 31

The purpose of staggered ignition is to compensate for?

Answer 31

diluted fuel/air mixture around the exhaust valve

Question 32

Aircraft mageto housings are usually ventilated in order to?

Answer 32

Provide cooling and remove corrosive gases produced by normal arcing.

Question 33

Failure of an engine to cease firing after turning a Magneto switch off is an indication of?

Answer 33

An open P-lead to ground

Question 34

Alignment of the marks provided for the internal timing of a magneto indicates that the?

Answer 34

The magneto is in the E gap position

Question 35

When using a timing light to time a magneto to an aircraft engine, the magneto switch should be placed in the?

Answer 35

BOTH Position

Question 36

The amount of voltage generated in any magneto secondary coil is determined by the number of windings and by the rate?

Answer 36

The rate of collapse of the magnet field around the primary coil

Question 37

When a magneto is operating, what is the probable cause for a shift in internal timing?

Answer 37

They can follower wear and/or the breaker points wear

Question 38

Magneto breaker point must be timed to open when the greatest?

Answer 38

the greatest field stress exists in the magnetic circuit

Question 39

Reference to shower of sparks ignition systems….
1. The retard breaker points are designed to keep the affected ignition system operating if the advanced breaker points should fail during normal engine operation after start. ❌️
2. The timed opening of the retard breaker point is designed to prevent engine “kick back” during start. ✔️

Answer 39

ONLY 2 is True

Question 40

A certain 9 cylinder radial engine used on non-compensated single unit, dual type Magneto with a 4 pole rotating magnet and separately mounted distributors. Which of the following will have the lowest RPM at any given speed?

Answer 40

Distributors

Question 41

The electrical circuit from the spark plug back to the magneto is completed by grounding through the?

Answer 41

engine structure

Question 42

What should be used to clean grease or carbon tracks from capacitors or coils that are used in magnetos?

Answer 42

Acetone