Chapter 7
Q. 7.2
Two long parallel wires are at a distance of 15 cm as shown in Fig. 7.4. If I_{1} = 50 A, what should be the value and direction of the current I_{2} such that the magnetic field intensity at point P is zero?
Step-by-Step
Verified Solution
At point P
H_{1} (I_{1}) = \frac{50}{2π (15 + 10) × 10^{-2} } A/m
H_{2} (I_{2}) = \frac{I_{2}}{2π × 10 × 10^{-2} } A/m
For net H at P to be zero
H_{1} + H_{2} = 0 or H_{2} = -H_{1}
or \frac{I_{2}}{2π × 10 × 10^{-2} } = \frac{50}{2π × 10 × 10^{-2}}
or
I_{2} = – 50 × \frac{10}{25} = –20 A (in opposite direction to I_{1})