The electric resistance of a particular wire of iron is R. If its length and radius are doubled, then:

 1 The resistance will be halved and the specific resistance will remain unchanged 2 The resistance will be halved and the specific resistance will be doubled 3 The resistance and the specific resistance, will both remain unchanged 4 The resistance will be doubled and the specific resistance will be halved
Subtopic: Â Combination of Resistors |
Â 82%
From NCERT
AIPMT - 2004
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Resistances $$n$$, each of $$r$$ ohm, when connected in parallel give an equivalent resistance of $$R$$ ohm. If these resistances were connected in series, the combination would have resistance in ohms, equal to:
1. $$\dfrac{R}{n^2}$$
2. $$\dfrac{R}{n}$$
3. $$nR$$
4. $$n^2R$$

Subtopic: Â Combination of Resistors |
Â 79%
From NCERT
AIPMT - 2004
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When a wire of uniform cross-section a, length l, and resistance R is bent into a complete circle, the resistance between any two diametrically opposite points will be:

1. R/2

2. R/4

3. R/8

4. 4R

Subtopic: Â Combination of Resistors |
Â 71%
From NCERT
AIPMT - 2005
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