Assertion and reason

Exercise and reference answers

Questions

1. Reason

   Thermal excitation produces electrons and holes as an intrinsic property.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   A pure semiconductor conducts a little even with no impurity added.

2. Reason

   Metals, semiconductors and insulators occupy separate resistivity ranges.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   Resistivity alone can classify a material.

3. Reason

   Semiconductors have intermediate resistivity.

   Verdict

   The assertion is false and the reason is true.

   Assertion

   Copper is a semiconductor.

Explanation