NEET-XII-Physics
36: Permanent Magnets
- #3A uniform magnetic field of 0.20 × 10-3 T exists in the space. Find the change in the magnetic scalar potential as one moves through 50 cm along the field.Ans : Given:
Magnetic field in the space, B = 0.20 × 10-3 T
Distance moved, `` ∆r`` = 50 cm
We know,
`` B=-\frac{dV}{dl}``
`` \Rightarrow dV\mathit{=}{\mathit{\int }}_{{r}_{1}}^{{r}_{2}}\mathit{-}\stackrel{\mathit{\rightharpoonup }}{B\mathit{.}}\,\mathrm{\,d\,}l``
`` ``
Since the magnetic field is uniform, it can come out of the integration sign.
`` \Rightarrow ∆V\mathit{=}\mathit{-}B\mathit{.}(∆r)``
`` ``
Here, `` ∆V`` is the change in the potential.
∴ Change in the potential = -0.2 × 10-3 × 0.5
= -0.1 × 10-3 T-m
Here, the negative sign shows that the potential decreases.
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