Question

Pls help me with my phyisics que. Show ur working :)​

Answer 1

i. Refer to the attachment for the answer.

ii. Magnetic moment of the coil = m

Total number of turns, N = 500

Cross-sectional rea, A = 1.26 × 10⁻⁴

Current passed through the coil, I = 100 μF = 100 × 10⁻⁶ F

Now, m = NIA

• m = 500 × 100 × 10⁻⁶ × 1.26 × 10⁻⁴

• m = 63000 × 10⁻¹⁰

• m = 0.0000063

• m = 6.3 × 10⁻⁶ Am²

$\bold{Hope\;it \; helps\;!}$

Answer 2

Question 1:

To show the harmonics in a stretched string between two rigid supports.

Solution:

• Since we are considering two rigid supports as the boundary for the superimposition of waves, the supports will act as NODES.

• Now, considering nodes as the supports, we can imagine infinite possibilities with anti-nodes and other nodes inbetween the supports.

• Some of the cases are attached in the diagram.

General equation will be :

• Length of wire be l

$\therefore \: l = \dfrac{n \lambda}{2}$

$\implies \: \nu = \dfrac{v}{ \lambda}$

$\implies \: \nu = \dfrac{v}{( \frac{2l}{ n} )}$

$\implies \: \nu = \dfrac{nv}{2l}$

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Question 2:

A circular coil with 500 turns and area 1.26 × 10^(-4) m² has a current of 100$\mu A$. Calculate the magnetic moment.

Answer:

• Magnetic moment is a vector, so we will consider the vector to be directed along the area vector.

• Let the unit area vector be $\hat{a}$

$\therefore \: \vec{M} = \bigg( n \times i \times |a| \bigg) \hat{a}$

$\implies \: \vec{M} = \bigg( 500 \times 1.26 \times {10}^{ - 4} \times 100 \times {10}^{ - 6} \bigg) \hat{a}$

$\implies \: \vec{M} = \bigg( 5 \times 1.26 \times {10}^{ - 6} \bigg) \hat{a}$

$\implies \: \vec{M} = \bigg( 6.3 \times {10}^{ - 6} \bigg) \hat{a}$

$\implies \: \vec{M} = \bigg( 6.3 \times {10}^{ - 6} \bigg) \hat{a} \: \: \: \: amp \: {m}^{2}$

So, magnetic moment is 6.3 × 10^(-6) Am².