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[Maximum number: 5]

A rod, R , lies perpendicular to a uniform magnetic field B of strength 0.50 T directed into the plane of the page. R is connected to a circuit and the electric current $I_{\mathrm{R}}$ is 2.0 A .

(a)

A small coil of wire of radius 2.0 cm and 20 turns is now located with its centre 10.0 cm from R. The current in R is kept constant at 2.0 A .

[ 5 ]

(i)

Explain why there is no current induced in the coil.

[ 2 ]

the magnetic field produced by the wire $/ \mathrm{I}_{\mathrm{R}}$ is constant.

therefore the «magnetic» flux/field through the coil is constant.

(ii)

The current in R increases at a constant rate from 2.0 A to 10.0 A in 0.5 seconds.

Calculate the emf induced in the coil.

[ 3 ]

$\begin{aligned} \Delta \mathrm{B}=\frac{\mu_{0}}{2 \pi}\left(\frac{10-2}{0.1}\right) \text { OR } 2 \times 10^{-5}-4 \times 10^{-6}=1.6 \times 10^{-5}<\mathrm{T} \gg \Delta \phi=A \Delta \mathrm{~B}=(\pi)\left(0.02^{2}\right)\left(\left(2 \times 10^{-5}\right)-\left(4 x 10^{-6}\right)\right)=2.5 \times 10^{-8}-5.03 \times 10^{-9} =2.01 \times 10^{-8}<\mathrm{Wb}> \varepsilon=\frac{n \Delta \phi}{\Delta t}=\frac{(20)\left(2.01 \times 10^{-8}\right)}{0.5}=8.0 \times 10^{-7}<\mathrm{V} \gg \end{aligned}$

IB Physics HL D 4 2 Hl Faradays Law Topic Practice

Question 1

Question (a)

Question (i)

Question (ii)