MCQ
Force between two identical bar magnets whose centres are $r $ metre apart is $ 4.8\, N$ , when their axes are in the same line. If separation is increased to $2r,$ the force between them is reduced to.....$N$
- A$2.4$
- B$1.2$
- C$0.6$
- ✓$0.3$
✓
Answer
Correct option: D.
$0.3$
d
(d)In magnetic dipole, force $ \propto \frac{1}{{{r^4}}}$
Hence new force $ = \frac{{4.8}}{{{2^4}}} = \frac{{4.8}}{{16}} = 0.3\;N$
(d)In magnetic dipole, force $ \propto \frac{1}{{{r^4}}}$
Hence new force $ = \frac{{4.8}}{{{2^4}}} = \frac{{4.8}}{{16}} = 0.3\;N$
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