Question

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​​

Answer 1

Answer :

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.