Test Index

Magnetism and Matter

Section: Physics

© examsnet.com

Question : 10 of 75

Marks: +1, -0

A bar magnet has total length

2 l = 20

units and the field point

P

is at a distance

d = 10

units from the centre of the magnet. If the relative uncertainty of length measurement is

1\%

, then uncertainty of the magnetic field at point

P

[28 Jan 2025 Shift 2]

$10\%$
$5\%$
$3\%$
$4\%$

Solution: 👈: Video Solution

Magnetic field at

P, B = \;\frac{\mu_0}{4\pi} \;\frac{m(2l)}{r^3}

, where

m

is the pole strength

\Rightarrow \left( \;\frac{\Delta B}{B} \times 100 \right) \;= \left( \;\frac{\Delta l}{l} \times 100 \right) + 3\left| \;\frac{\Delta r}{r} \right| \times 100

\;=1\%+3\%=4\%

© examsnet.com

Go to Question:

Prev Question

Next Question