Assertion and reason

Exercise and reference answers

Questions

1. Reason

   Electrons collide with ions at regular intervals, which caps their speed.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   Drift velocity is proportional to the applied field, not to acceleration.

2. Reason

   Many substances obey it, but several well known ones do not.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   Ohm's law is not a fundamental law of nature.

3. Reason

   emf is the work done per unit charge by the source.

   Verdict

   The assertion is false and the reason is true.

   Assertion

   emf is a kind of force.

4. Reason

   Some potential is dropped across the source's internal resistance.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   Terminal voltage falls when current is drawn.

Explanation