Looking for classes? Ksquare Career Institute, Bengaluru →
Moving Charges and Magnetism
Magnetic Field of a Solenoid
3 questions from 3 papers, each with its answer.
- questions
- 3
- papers
- 3
- years asked, 2017–2026
- 2 of 10
- of Moving Charges and Magnetism
- 3.37%
Appears in
Concepts tested
- B = μ0 n I 2
- B = mu0 n i
All Questions
2022 1 question
-
A long solenoid of radius 1 mm has 100 turns per mm. If 1 A current flows in the solenoid, the magnetic field strength at the centre of the solenoid is :$B = \mu_0 n i = \mu_0\frac{N}{\ell}i$ $n = 100$ turns per mm $= \frac{100}{10^{-3}}$ turns per m $B = 4\pi \times 10^{-7} \times \frac{100}{10^{-3}} \times 1 = 12.56 \times 10^{-2}$ T
2020 1 question
-
A long solenoid of 50 cm length having 100 turns carries a current of 2.5 A. The magnetic field at the centre of the solenoid is: ($\mu_0=4\pi\times10^{-7}\ T\,m\,A^{-1}$)$B = \mu_0 nI$, with $n = \frac{N}{L} = \frac{100}{50 \times 10^{-2}} = 200$ turns/m $B = 4\pi \times 10^{-7} \times 200 \times 2.5 = 6.28 \times 10^{-4}$ T
2003 AIPMT 1 question
-
A long solenoid carrying a current produces a magnetic field B along its axis. If the current is doubled and the number of turns per cm is halved, the new value of the magnetic field is -Magnetic field inside a long solenoid: $B = \mu_0 n i$, where n is the number of turns per unit length.
New values: $n' = \dfrac{n}{2}$, $i' = 2i$
$B' = \mu_0 n' i' = \mu_0 \cdot \dfrac{n}{2} \cdot 2i = \mu_0 n i = B$
So the magnetic field remains B.