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EMI

EMI

by Chandni Bhatia -
Number of replies: 1

Consider  two wires P1Q1 AND P2Q2. Both of them are sliding on smooth rails.The wires have a resistance of 2ohms.moving with same speed equal to 5cm/s and are connected to a 19 ohm resistor.The length of the wires is same and is equal to 4cm/s.Magnetic field is into the page and is 1T. Find the current in 19 ohm resistor when the wires are moving to the right.

I have one more doubt in this that when the wires are moving to the right and magnetic field is inside the page, emf is induced in the wires and thus, batteries are generated. Both of these batteries have higher potential at the top and lower potential at the bottom.Thus, batteries are opposing each other and hence there should be no current in the circuit at all.   But when I did mathematics of this question I found that current in the 19 ohm resistor is 1 mA. However answer is 0.1mA.Please answer my doubt .

In reply to Chandni Bhatia

Re: EMI

by Shashank Todwal -

Well Chandni,

I am getting ans as 0.1 mA.I think you must have made mistake in calculating cell volatage which comes 0.002V and not 0.02V.And as far your 2nd question is concerned,your result is true only in case where an ext wire joining the high voltage to low voltage  is absent(which is not true here because we have wire having 19 ohm res.connecting high to low voltage.So current flows through it.

I hope I cleared your doubt.

Bye!!! Best Luck