Question

A copper wire of resistance R is cut into ten parts of equal length. Two pieces each are joined in series and then five such combination are joined in parallel. The new combination will have resistance

Answer 1

Answer:

R/25

Explanation:

Resistance of a piece of wire is given by R=¶L/A where ¶ is resistivity

Since we cut the same wire into equal pieces(10) resistance of each piece is given by R/10. When two are connected in series, resistance is given by R/10+R/10=2R/10=R/5

When 5 resistors of r=R/5 are connected in parallel to each other, resistance is given by R/25 on applying parallel connection formula

Hope the answer helped you