Question

A wire PQRST carrying current I=5A is placed in uniform magnetic field B=2T as shown in figure If the length of part QR=4 cm and SR=6 cm then the magnetic force on SR edge of the wire is:

• A. 0.4 N
• B. 0.6 N
• C. zero
• D. 6N

Answer 1

The correct option is A 0.4 N

Given that,

SR = 6 cm

QR = 4 cm

Magnetic force on arm SR is $F=BIL\sin \theta$

Where, B is magnetic field

From the figure, $\sin \theta =\frac{4}{6}=\frac{2}{3}$

So, $F=2\times 5\times 0.06\times \frac{2}{3}$

$F=0.4N$