Question

2 copper wires a and b of length 30 m and 10 m have radii 2 cm and 1 cm respectively compare the resistance of 2 wires​

Answer 1

Answer:

Step-by-step explanation:

Length of First Copper Wire = $l_{1}$ = 30 m = 3000 cm

Radius of First Copper Wire = $R_{1}$ = 2 cm

Area of cross section of Wire 1 = $\pi R_{1} ^{2}$ = $4\pi$ = $A_{1}$

Resistance of 1st Wire = $\frac{(rho) l_{1}}{A_{1} }$ = $\frac{3000}{4\pi }$ = $R_{1}$

Length of Second Copper Wire = $l_{2}$ = 10 m = 1000 cm

Radius of Second Copper Wire = $R_{2}$ = 1 cm

Area of cross section of Wire 2 = $\pi R_{2} ^{2}$ = $\pi$ = $A_{2}$

Resistance of 2nd Wire = $\frac{(rho) l_{2}}{A_{2} }$ =  = $R_{2}$

Now,

$R_{1}$ : $R_{2}$ = $\frac{3000}{4\pi }$ :  $\frac{1000}{\pi }$ = $\frac{3}{4}$ : $\frac{1}{1}$ = 3 : 4

HOPE THIS HELPS YOU!