Capacitors are used in the induction coil to

Analyze the question: It asks about the purpose of a capacitor in an induction coil. An induction coil has a primary coil (few turns, thick wire) and a secondary coil (many turns). An interrupter (make-and-break contact) repeatedly cuts the primary current, which induces a very high voltage in the secondary.

Explain the concept: When the interrupter breaks the primary circuit, the collapsing magnetic field induces a large back e.m.f. in the primary coil (self-induction). This back e.m.f. can make a spark jump across the gap of the interrupter contacts. This causes two problems:

1. The contacts burn and wear out.
2. The spark lets the primary current die away slowly instead of stopping abruptly. The magnetic flux then collapses slowly, so the e.m.f. induced in the secondary is much smaller.

Role of the capacitor: A capacitor is connected across the interrupter contacts. It absorbs the surge of current and the self-induced e.m.f. when the circuit breaks, so no spark forms at the contacts. The current then stops quickly and the flux collapses rapidly, giving a much higher induced voltage in the secondary.

Checking the options:

• A. Control circuits: not its function here.
• B. Prevent distortion of electric fields: not relevant.
• C. Prevent electric sparks: correct. It suppresses sparking at the interrupter contacts.
• D. Dissipate energy: a capacitor stores energy temporarily and does not dissipate it. That is the job of a resistor.

Tip: Remember "capacitor in the induction coil = spark suppressor." It protects the contacts and makes the break sharp, which increases the output voltage. A similar capacitor is used across the contact breaker in a car's ignition system.