Electromagnetic Induction and Alternating Current 1 Question 2
2. A $10 m$ long horizontal wire extends from North-East to South-West. It is falling with a speed of $5.0 ms^{-1}$ at right angles to the horizontal component of the earth’s magnetic field of $0.3 \times 10^{-4} Wb / m^{2}$. The value of the induced emf in wire is
(a) $1.5 \times 10^{-3} V$
(b) $1.1 \times 10^{-3} V$
(c) $0.3 \times 10^{-3} V$
(d) $2.5 \times 10^{-3} V$
(Main 2019, 12 Jan II)
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Answer:
Correct Answer: 2. (a)
Solution:
- Wire falls perpendicularly to horizontal component of earth’s magnetic field, so induced electromotive force $(\varepsilon)$ $=B l v$
Substituting the given values, we get
$$ \varepsilon=0.3 \times 10^{-4} \times 10 \times 5=1.5 \times 10^{-3} V $$
