Two similar poles repel each other with a force of 0.005 N when placed 16 cm apart. If they are placed 8 cm apart, what will be the repulsing force ?

Options

A. 0.001 N
B. 0.002 N
C. 0.01 N
D. 0.02 N

Answer

D

Explanation

Force between two magnetic poles is given by, `F=(mu_(0))/(4pi)=(m_(1)xxm_(2))/(r^(2))" or "Fprop(1)/(r^(2))`
Thus `" "(F_(1))/(F_(2))=(r_(2)^(2))/(r_(1)^(1))=((8)/(16))^(2)=((1)/(2))^(2)" or "(F_(1))/(F_(2))=(1)/(4)`
or `" "F_(2)=4xxF_(1)=4xx0.005=0.02N.`