NCERT Class XII Chapter
Moving Charges and Magnetism
Questions With Solutions

© examsnet.com
Question : 7
Total: 28
Two long and parallel straight wires A and B carrying currents of 8.0 A and 5.0 A in the same direction are separated by a distance of 4.0 cm. Estimate the force on a 10 cm section of wire A.
Solution:  
Force of attraction per unit length on two parallel wires carrying current in same direction.
F/l =
µ0
4Ï€
2I1I2
r
= 10−7 ×
2×8×5
4×10−2
= 20 × 10−5 N m−1
Attractive force on 10 cm section of wire A
F = [20 × 10−5] [10 × 10−2] = 2 × 10−5 N
© examsnet.com
Go to Question: