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If the resistance of a conductor of length 1 cm and area of cross-section 1 \(\tt cm^{2}\) be 1 ohm, its resistance will be

1 ohm
1 ohm-cm
1 ohm-metre
1 ohm/cm

Cross-section of a copper wire is 0.01 \(\tt cm^{2}\) its length is 1 metre the resistivity of copper at \(\tt 18^{0}\) c is \(1.78\times 10^{-6}\) ohm-cm. Its resistance will be

0.0256 ohm
0.0178 ohm
\(1.78\times 10^{-4}\)
1.78 ohm

Two conducting wires are made of some material, if wire be 4 times and that of 1st wire 3 then the ratio of their resistance will be

4:1
1:4
16:1
1:16

If the length of a copper conductor be increase by 4 times keeping the cross-section unchanged at a definite temperature, the resistivity

will be 4 times of the initial resistivity
will be \(\frac{1}{4}\) times of the initial resistivity
remains unchanged
will be 16 times of the initial resistivity

Keeping the length unchanged if the area of cross-section of a conductor be increased by 4 times the current will be

4 times of the initial current
\(\frac{1}{4}\) part of the initial current
4 times of the initial current
\(\frac{1}{16}\) part of the initial current

Physics

Ten Standard

Test your understanding of this lesson Numerical problem related to heating effect of current:-

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