Question

2. A current of 3.5 ± 0.5 A flows through metallic conductor with a potential difference of 21 ± 1 V is applied. Find the resistance of the wire.

Answer 1

Answer:

Explanation:

=> It's given that,

Current through the wire, I = 3.5 ± 0.5 A  

Potential difference, V =  21 ± 1 V  

Resistance , R = ?

=>  As per the Ohm's law:

V = IR

∴ R = V / I

Resistance without error, R = V/I = 21/3.5 = 6ᘯ.

=> We can do the calculation of error in resistance as below:

∆R/R = ∆V/V + ∆I/I

∴ ∆R/6 = 1/21 + 0.5/3.5  

∆R/6 = (1/21 + 1/7)

∆R = 6 × 4/21  

∆R = 24/21

∆R = 8/7

∆R ≈ 1.143  

∴  R = (6 ± 1.143) Ω.

Thus, the resistance of the wire is (6 ± 1.143)  Ω