A coil has an average induced current of 230 A. In a time of 0.1 s through one turn of a 24-turn coil of wire, the magnetic flux reduced to 6 Wb from 11 Wb.

1. Calculate the wire's resistance,
2. If the current is reduced to 115 A, calculate the wire resistance.

Dear student, page ! In question 2, the current is reduced to 115 AS Something must have been dove. enty two things are, possible - Case 1: we assume EMF is the same i.e. 120 0 v. The current is 115A - Resistance by simple ampplication of ohm's law = 1200 2 = 10. 4452 115 But in this scenario we've to change the wine itself. Resistance = 8 8 = Resistivity A I = length of the total wipe it A = Area of cross - section of the wine. we see if we keep these 3 things ( 3, 2, A) the same under no circumsta rices can the resistance charge But here it has changed from 5. 2252 to 10.4 452 ,= ), Either of Atleast ove of 8,2, A is changed. and when any one of 8, 2, A is changed . itself that amounts to changing the wire,. So we this scenario , is less likely to be trove as there is no mention of chang- -ing the wolfe in the question.Page ? So we are left with the only caseine. Case 2: EMF = Current X Resistance. - Now current is reduced. we can't change the wine because the question does not permit us to do so, =) For consistency we have to reduce the EMF. From Faraday's Law, How Can we EMF = -N dQB Magnetic flux. NE No of turns in the coil of wine. N = 24 initially, spoils tou Here ". Initially, EMF = - 24 At bout a or (magnitude ) 90 0 0 0- 24 AtPage 3 Now there are we can change bdamp by these woolys: EMP a) keeping no of turing the same but changing ( AP) 1 14 9 6) Change no of turns but keeping Ack! the same. ( A$ 1 = Rate of change of flux through a single turn. We choose to do the latter just by our Choice. @ By changing our magnetic field setup we ensure that (A 108 / is And1, not changed. But now , we change the number of turons. From(1 ) : we see if current is reduced by half =) EMF is also reduced, by half ! weare changing, the no of turns only -) No of turing should be reduced by half. from, 24-turn cold we reduce it to a 24 = 12 - turn coll. that will 2