Starting Systems Questions and Answers

Answer: C

Pressing the button asks the controller to crank, and it releases the starter automatically once the engine fires. That prevents the driver holding the key against a running engine. Key verification does add a brief delay, which makes the last option partly true. Reading the definition literally, rather than recalling a summary, avoids the usual confusion. The order in which the effects act is what decides the outcome, so it is worth establishing first.

Answer: D

The pinion meets a ring gear turning far faster and the teeth are chewed away. The one way clutch protects the armature, so the motor itself survives. Automatic release exists precisely to prevent it. Most errors here come from carrying across a result from a neighbouring case where it does not hold. Checking which component actually carries the load settles most questions of this kind at once. Naming what changes and what stays the same is the reliable route through questions of this shape.

Answer: A

A damaged ring gear will destroy the new starter, so it is turned through and inspected before fitting. The old pinion's condition genuinely does indicate ring gear wear, which makes the last option a real part of the same inspection. Naming what changes and what stays the same is the reliable route through questions of this shape. Tracing the requirement back to the physical constraint that produces it makes the answer follow. The shared properties explain why these belong to one family, and the differences explain why more than one exists.

Answer: B

Damage confined to part of the ring gear produces grinding only when the engine stops in certain positions. Failure to disengage does rattle, which makes the last option a genuine separate fault worth distinguishing. Working the distinction through on a single concrete case fixes it more firmly than any rule of thumb. The shared behaviour explains why these belong together and the differences explain why both exist. A limit that survives making every external component ideal is an intrinsic one, and worth knowing for that reason.

Answer: C

A bench test measures no load current and speed against specification, revealing tight bearings or a rubbing armature. Cranking current is measured on the vehicle and is a different test. Both figures appear in the data. A symptom that appears under one condition and not another is what narrows the diagnosis quickly. Reading the definition literally, rather than recalling a summary, avoids the usual confusion. Framing the question as which quantity the change acts upon makes the answer follow without calculation.

Answer: D

Excess current with low speed means work is being absorbed, whether by tight bearings, a bent shaft or a shorted winding. Worn brushes give low current and low speed instead, which is the opposite pattern. The order in which the effects act is what decides the outcome, so it is worth establishing first. Most errors here come from carrying across a result from a neighbouring case where it does not hold. Working the distinction through on a single concrete case fixes it more firmly than any rule of thumb.

Answer: A

Brushes press on a segmented commutator, which also reverses the current in each coil as it passes the neutral plane. Slip rings are continuous and are used where no reversal is needed, such as an alternator rotor. Checking which component actually carries the load settles most questions of this kind at once. Naming what changes and what stays the same is the reliable route through questions of this shape. A symptom that appears under one condition and not another is what narrows the diagnosis quickly.

Answer: B

Segmented construction switches each coil as it crosses the neutral plane so the torque remains in one direction. Without that reversal the armature would stop after half a turn. It is what makes a direct current motor possible. Tracing the requirement back to the physical constraint that produces it makes the answer follow. Working the distinction through on a single concrete case fixes it more firmly than any rule of thumb. Reading the definition literally, rather than recalling a formula, is the reliable route through questions of this shape.

Answer: C

A commutator is skimmed true and the mica undercut so it does not stand proud as the copper wears. Light polishing genuinely does refresh a lightly worn surface, which makes the last option a real if limited remedy. Replacement is required when the diameter reaches its limit. The shared behaviour explains why these belong together and the differences explain why both exist. A symptom that appears under one condition and not another is what narrows the diagnosis quickly.

Answer: D

Mica is harder than copper, so it stands proud as the copper wears and lifts the brushes, which arcs and destroys the commutator. Copper smearing across the mica is a genuine machining fault too, which makes the last option a real concern. Naming the cost of a choice alongside its benefit is what turns a fact into a design decision. The order in which the effects act is what decides the outcome, so it is worth establishing first.