Question

1. A 4ohm wire is doubled on it . calculate the new resistance of the wire ? 2. A metal wire of resistivity 64×10to the power -6 ohm and length 198cm has a resistance of 7 ohm . calculate its radius ?​

Answer 1

1 : If a 4 ohm resistance wire is doubled and connected in series 4 +4 =8 ohms it will be,or if it is connected in parallel it will be 1/4+1/4 =2 ohms .as per the formula R =r1 +r 2 if they are connected in series, if they are connected in parallel, 1 /R =1 /r1 +1/r2.