The resistance of a metallic wire is
Adirectly proportional to its area of cross-section
Bdirectly proportional to its length
Cinversely proportional to its length
Dindependent of the material
Answer & Solution
Correct answer: B. directly proportional to its length
1. R = ρl/A.
2. So resistance is **directly proportional to length l** and inversely proportional to area A.
3. A longer wire (or a thinner wire) has more resistance; the material's resistivity ρ also matters.
_Source: Karnataka SSLC (KSEEB) Class 10 Science, Ch12 'Electricity', §12.4 (R = ρl/A)_
Related questions
If the resistance of a component is kept constant and the voltage across it is doubled, thDomestic electrical appliances are connected in parallel rather than in series mainly becaThe commercial unit of electrical energy, '1 unit', isA potential difference of 12 V is applied across a $4\ \Omega$ resistor. The current throuJoule's law of heating states that the heat produced in a resistor isThe electric power dissipated in a resistor can be written asTwo resistors, each of resistance $R$, are connected in parallel. Their equivalent resistaFor resistors in parallel, the reciprocal of the equivalent resistance equals