simple one!-- --

P and Q are two coaxial conducting loops separated by some distance. Wen te switch S is closed, a clockwise curent i1 flows in P and an indused current I1 flows in Q. The switch remains closed for a long time. Wen S is opened, a current I2 flows in Q.
then directions of 11 and I2 are:

1)respectively clockwise and anticlockwise.
2)both clockwise
3)both anticlockwise
4)resp. anti-cl and clockwise.

15 Answers

1
Pavithra Ramamoorthy ·

i cldn get the last line of d ques...............

1
skygirl ·

oops i will edit it..

1
skygirl ·

yes, have edited it... :)

1
Pavithra Ramamoorthy ·

option 1)...... say whether correct..... i ll proceed wit ma explanation....

1357
Manish Shankar ·

Initially As the switch is closed, magnetic field due to loop P is towards left

Now the current is induced in Q such that the magnetic field due to Q is opposite to P...... so current in Q is anticlockwise

Now when the switch is opened the current in loop Q will be clockwise

so the answer is (d)

1
skygirl ·

its a only...

1
Grandmaster ·

i think option 4 is correct as if initially the i in I1 clockwise the mag flux is increasing in I2 hence an anticlockwise current will grow to equalise the flux. then when circuit is closed the case is reversed

1
skygirl ·

plz explain wat will happen afetr switch is opened///

1
Pavithra Ramamoorthy ·

after seein manish byahs post.. got a doubt whether d current thro q ll remain in sam direction after key s opened..........

1
Pavithra Ramamoorthy ·

manish byah.. may i kno whether d current thro q is momentary????????

11
Anirudh Narayanan ·

Firstly the magnetic flux points left. Then as the current increases clockwise, q tries to oppose increase in flux towards left. So it sets up a current which increases magnetic field towards the right. So current in q will be anticlockwise :)

11
Anirudh Narayanan ·

So option (a) is correct

1
dimensions (dimentime) ·

there is one special thing about this question,
FROM WHICH DIRECTION WE OBSERVE CURRENT????????

when we observe current in Q from right side of Qthen (d) is correct

when we observe current in Q from left of Q (or P)
then (a) is correct.

the direction of observation must be specified......

RIGHT???????????//

1
skygirl ·

yes you are r8!
i think fiitjee ppl took it from left..
nothing is mentioned in the question...

1
Grandmaster ·

see the assertion of direction current is right ,but whatever be the direction understanding change in flux and its after effect on current is imp,so whatever happens the ans is either a) or d).

Plz comment..

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