- Home
- Standard 12
- Physics
5.Magnetism and Matter
medium
A tangent galvanometer shows a deflection $45^o $ when $10\, mA$ current pass through it. If the horizontal component of the earth’s field is $3.6 \times {10^{ - 5}}\,T$ and radius of the coil is $10\, cm$. The number of turns in the coil is......$turns$
A
$5700$
B
$57$
C
$570$
D
$5.7$
Solution
(c) $K = \frac{{2r{B_H}}}{{{\mu _0}n}}$
or $n = \frac{{2r{B_H}}}{{{\mu _0}K}} = \frac{{2 \times 0.1 \times 3.6 \times {{10}^{ – 5}}}}{{4\pi \times {{10}^{ – 7}} \times 10 \times {{10}^{ – 3}}}}$ $ = \frac{{1.8 \times {{10}^3}}}{{3.14}} = 570$
Standard 12
Physics
