Starting Systems Questions and Answers

Answer: A

Tapping frees a sticking plunger or shifts a worn brush into contact. A commutator dead spot produces exactly the same symptom and is a genuine cause, which makes the last option a real alternative rather than a distractor. The shared behaviour explains why these belong together and the differences explain why both exist. Tracing the requirement back to the physical constraint that produces it makes the answer follow. A symptom that appears under one condition and not another is what narrows the diagnosis quickly.

Answer: B

Labour cost usually makes replacement cheaper than overhaul, and remanufactured units carry a warranty. Solenoid replacement genuinely does cure many failures and is often worth trying, which makes the last option a real economical option. Naming the cost of a choice alongside its benefit is what turns a fact into a design decision. The shared behaviour explains why these belong together and the differences explain why both exist.

Answer: C

Solenoids are commonly available separately because contact erosion is a frequent failure. Brushes and bushes are the other common service parts. Armatures and gear sets are genuinely available for some heavy duty units, which makes those options partly real. Reading the definition literally, rather than recalling a summary, avoids the usual confusion. Naming the cost of a choice alongside its benefit is what turns a fact into a design decision.

Answer: D

Each engagement draws an arc that removes metal, and eventually the contacts cannot pass the current. Heat softening genuinely contributes, which makes the last option part of the same mechanism. Contact kits are available for many solenoids. Most errors here come from carrying across a result from a neighbouring case where it does not hold. Reading the definition literally, rather than recalling a summary, avoids the usual confusion.

Answer: A

Resistance at the contacts starves the motor progressively until nothing happens. Welded contacts genuinely do occur and produce a starter that will not stop, which makes the last option a real and alarming failure mode. Naming what changes and what stays the same is the reliable route through questions of this shape. Most errors here come from carrying across a result from a neighbouring case where it does not hold. The order in which the effects act is what decides the outcome, so it is worth establishing first.

Answer: B

Welded contacts keep the motor powered regardless of the key, so the battery must be disconnected before the starter destroys itself. Switching off is the first thing anyone tries, which is why it makes such a plausible distractor. Working the distinction through on a single concrete case fixes it more firmly than any rule of thumb. Naming what changes and what stays the same is the reliable route through questions of this shape.

Answer: C

The switch carries only the relay coil current of a few amps rather than the solenoid current of thirty or more. Diodes genuinely are fitted across relay coils to absorb the spike, which makes the last option a real component with a different purpose. Reading the definition literally, rather than recalling a summary, avoids the usual confusion. The shared behaviour explains why these belong together and the differences explain why both exist.

Answer: D

A flyback diode gives the collapsing field a path and prevents a spike reaching the switching transistor. Contact arcing does dissipate the energy, which makes the last option describe exactly the damage the diode is fitted to prevent. Most errors here come from carrying across a result from a neighbouring case where it does not hold. Naming the cost of a choice alongside its benefit is what turns a fact into a design decision.

Answer: A

Reversed, the diode conducts directly across the supply and the fuse opens immediately. Direct current has no half cycles, so the last option describes an alternating current phenomenon that cannot apply here. Naming what changes and what stays the same is the reliable route through questions of this shape. Reading the definition literally, rather than recalling a summary, avoids the usual confusion.

Answer: B

Many solenoids include an auxiliary contact set that acts as the relay, so no separate relay is fitted. The one way clutch belongs to the drive assembly rather than the solenoid. Integration reduces the component count. Working the distinction through on a single concrete case fixes it more firmly than any rule of thumb. Most errors here come from carrying across a result from a neighbouring case where it does not hold.