Q11.Current of 5A flows through 2 conductors A and B , which have the potential difference of 100V and 200V respectively . If the resistance through A and B be R and r , then
a) R=r
b)R=2r
c) r=2R
d) r=4R
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Current of 5A flows through two conductors A and B, which have the pd of 100V and 200V respectively.
Resistance of conductor A = R
Resistance of conductor B = r
We have to find relation b/w R and r
★ As per ohm's law, current flow through a conductor is directly proportional to the applied potential difference. (at constant temperature)
- V = I × R
where R denotes resistance of conductor
Resistance of conductor depends upon length of conductor, area of cross section and temperature.
★ For conductor A :
➠ V₁ = I × R₁
➠ 100 = 5R …… (I)
★ For conductor B :
➠ V₂ = I × R₂
➠ 200 = 5r …… (II)
Taking ratio of (I) and (II), we get
➝ 100/200 = 5R/5r
➝ 1/2 = R/r
➝ r = 2R
∴ (C) is the correct answer.
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