Physics, asked by ShivamKashyap08, 7 months ago

A flat coil of 500 turns each of area 50 cm², rotates in a uniform magnetic field of 0.14 Wb/m² about an axis normal to the field at an angular speed of 150 rad/s. The coil has a resistance of 5Ω. the induced e.m.f is applied to an external resistance 10Ω. the peak current through the resistance is:- [Answer:- 3.5 A] \rule{300}{1.5} \rule{300}{1.5} A cylindrical magnet is kept along the axis of a circular coil. On rotaing the magnet about its axis, the coil will have induced in it:- 1) No current 2) A Current 3) Only an e.m.f 4) Both e.m.f and a current \rule{300}{1.5} Answer with Explanation. Thanks!

Answers

Answered by XEVILX
9

Hey Pretty Stranger!

 \sf \: Answer  \: 1 :

We're given with :

• N = 500

• A = 50 cm²

• B = 0.14 Wb/m²

• ω = 150 rad/s

• R = 5 Ω

• R' = 10 Ω

First of all, let's convert the Area into m² that would be

50 cm² = 50 × 10

Now,

   \star \:\sf \:   \: e_0 =NAB  \omega

  \sf  \longrightarrow  \:   \: e_0  = 500 \times 50 \times  {10}^{ - 4}  \times 0.14 \times  150

  \sf  \longrightarrow  \:   \: e_0  = 52.5

Now, Total Resistance would be

→ R + R' = 5 + 10 = 15 Ω

   \therefore \:\sf \:   \: i_0   = \dfrac{e_0}{total \: resistance}

   \longrightarrow \:\sf \:   \: i_0   =  \cancel\dfrac{52.5}{15}

   \longrightarrow \:\sf \:   \: i_0   = 3.5A \:

 \sf \: Answer  \: 2 :

When a magnet is kept along the axis and is rotated around its axis, no current will be induced in it because we know that the formula for flux is :

★ Φ = NBA = constant

\sf\: \therefore e = dΦ/dt = 0

 \large \sf \: i = 0

Hence, option i) is the required answer.

Adieu! ;)

Answered by Anonymous
5

1. Plz refer to attachment

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2. Induced electromotive force(e.m.f) and hence, induced electric current is produced if there is change in flux through a particular area by change in orientation or other reason.

The rotation of magnet causes change in magnetic flux in the coil.

Therefore,there will be induced current in the coil but it’s direction will be such so as to oppose the change in magnetic flux(Lenz’s law).

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