JEE MAIN - Physics (2003 - No. 8)
The length of a given cylindrical wire is increased by $$100\% $$. Due to the consequent decrease in diameter the change in the resistance of the wire will be
$$200\% $$
$$100\% $$
$$50\% $$
$$300\% $$
설명
$${R_f} = {n^2}{R_1}$$
Here $$n=2$$ (length becomes twice)
$$\therefore$$ $${R_f} = 4{R_i}$$
New resistance $$=400$$ of $${R_i}$$
$$\therefore$$ Increase $$ = 300\% $$
Here $$n=2$$ (length becomes twice)
$$\therefore$$ $${R_f} = 4{R_i}$$
New resistance $$=400$$ of $${R_i}$$
$$\therefore$$ Increase $$ = 300\% $$