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IMPORTANT
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A null point is found at 200 cm in potentiometer when cell in secondary circuit is shunted by 5 Ω. When a resistance of 15 Ω is used for shunting null point moves to 300 cm. The internal resistance of the cell is ______ Ω.

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Important Questions on Current Electricity

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JEE Main
IMPORTANT

If the potential difference between B and D is zero, the value of x is 1n Ω. The value of n is ______.

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JEE Main
IMPORTANT
Two identical cells, when connected either in parallel or in series gives same current in an external resistance 5 Ω. The internal resistance of each cell will be ______ Ω.
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JEE Main
IMPORTANT

The equivalent resistance between A and B of the network shown in figure:

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JEE Main
IMPORTANT
In an experiment to find emf of a cell using potentiometer, the length of null point for a cell of emf 1.5 V is found to be 60 cm. If this cell is replaced by another cell of emf E. the length-of null point increases by 40 cm. The value of E is x10 V. The value of x is ______.
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JEE Main
IMPORTANT
What equal length of an iron wire and a copper-nickel alloy wire, each of 2 mm diameter connected parallel to give an equivalent resistance of 3 Ω?
(Given resistivities of iron and copper-nickel alloy wire are 12 μΩ cm and 51 μΩ cm respectively)
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JEE Main
IMPORTANT
An electric bulb of 500 W at 100 V is used in a circuit having a 200 V supply. Calculate the resistance R to be connected in series with the bulb so that the power delivered by the bulb is 500 W.
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JEE Main
IMPORTANT
First, a set of n equal resistors of 10 Ω each are connected in series to a battery of E.M.F. 20 V and internal resistance 10 Ω. A current I is observed to flow. Then, the n resistors are connected in parallel to the same battery. It is observed that the current is increased 20 times, then the value of n is ___________.
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JEE Main
IMPORTANT
For full scale deflection of total 50 divisions, 50mV voltage is required in galvanometer. The resistance of galvanometer if its current sensitivity is 2 div /mA will be: