current-electricity Question 8
Question: Q. 8. Give an example of a material each for which temperature coefficient of resistivity is (i) positive, (ii) negative. U] [CBSE SQP 2015-2016]
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Solution:
Ans. (i) $\mathrm{Cu}$ (metals, alloys).
(ii) Si (semiconductor).
[CBSE Marking Scheme 2016]
[AI $Q$. 9. The emf of a cell is always greater than its terminal voltage. Why ? Give reason.
R [Delhi I, II, III 2013]
Ans. The emf of a cell is always greater than its terminal voltage as the cell has some finite internal resistance. It is seen that an emf is determined when the cell is in open circuit without any current drawn.
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[CBSE Marking Scheme 2013]
