Question:
The resistance of a wire is 24$O$. lt is so stretched that the length becomes four times, then the new resistance of wire will be
The resistance of a wire is 24$O$. lt is so stretched that the length becomes four times, then the new resistance of wire will be
Updated On: Jun 17, 2022
- $248 O$
- $298 O$
- $384 O$
- $428 O$
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The Correct Option is C
Solution and Explanation
In case of stretching of wire $R ? l^2$.
If length becomes 4 times, so resistance becomes 16 times,
ie,
$P'=16 \times 24=384 O$
If length becomes 4 times, so resistance becomes 16 times,
ie,
$P'=16 \times 24=384 O$
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Concepts Used:
Electromagnetic Induction
Electromagnetic Induction is a current produced by the voltage production due to a changing magnetic field. This happens in one of the two conditions:-
- When we place the conductor in a changing magnetic field.
- When the conductor constantly moves in a stationary field.
Formula:
The electromagnetic induction is mathematically represented as:-
e=N × d∅.dt
Where
- e = induced voltage
- N = number of turns in the coil
- Φ = Magnetic flux (This is the amount of magnetic field present on the surface)
- t = time
Applications of Electromagnetic Induction
- Electromagnetic induction in AC generator
- Electrical Transformers
- Magnetic Flow Meter