00:02
Hi, these are the magnetic field lines in the given problem representing a uniform magnetic field.
00:14
In this magnetic field, the fly is flying over which there is a coil wound.
00:23
Initially the plane of coil was perpendicular to the direction of magnetic field and after some time the plane of this coil become parallel to the magnetic field.
00:38
So it has been asked in the given problem, which of the following could double the emf produced when the fly turns 90 degree here like this.
00:50
So in option a, double the number of turns in the coil.
00:56
So we know the emf induced is having an expression n times of d5 by d t or we can say this is n times of n times of d t.
01:04
Or we can say this is n times of b2 or we can say just 5 2 not b2 this is 5 2 the final flux minus initial flux so this is 5 2 minus 5 1 divided by time or we can say this is n times of b a cos 90 degree because finally the angle between area vector and magnetic field vector is 90 degree while initially it was 0 degree so this is b a cos 90 degree and this is minus so cost 90 degree and d a cause zero degree initially it was 0 degree divided by time so finally the expression for this emf induced comes out to be n b a by t this is minus here and this is 0 minus 1 so finally we can say emf induced is given by n b a by t so if we look at in option a, it says that double the number of turns in the coil.
02:17
So yes, this is sure.
02:19
The emf induced depends directly on the number of turns.
02:22
So on doubling the number of turns in the coil, the emf induced will become double.
02:27
So option a is correct.
02:29
In option b, double the coils area...