Question

Your friend needs 10 Ohm resistance. He came to you and asked, but

you have 40 ohm resistors.

i. How many resistors your friend will ask you?

ii. How the resistors which are taken are connected?

iii. Show that their effective is 10 ohms.​

Answer 1

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i) No of resistors to be given to friend :

$\frac{ohm \: resistors}{resistance \: required}$

In this case, I have ohm resistors = 40

Resistance required by friend = 10

Therefore Resistors I will give =

$\frac{40}{10} = 4$

Thus I will give him 4 ohm resistors of 40 resistance so that he can get 10ohm resistance.

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ii) To obtain the net resistance = 10ohm

My friend will connect the 4 resistors of 40 resistance in a parallel series so that the output resistance he will get will be equal to 10ohm.

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iii) Since I gave him 4 resistors of 40 resistance, thus the effective resistance will be:

$\frac{1}{r} = \frac{1}{40} + \frac{1}{40} + \frac{1}{40} + \frac{1}{40}$

$\frac{1}{r} = \frac{80}{1600} + \frac{80}{1600} \\ \\ \frac{1}{r} = \frac{160}{1600} \\ \\ \frac{1}{r} = \frac{1}{10}$

Thus we get effective resistance to be 10ohm.

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More to know :-

Dry cell :-

A dry cell consists of zinc container which contains paste of Ammonium Chloride, zinc chloride and manganese dioxide with powdered carbon . This paste acts as an electrolyte in this cell . There is a carbon rod dug inside the cell.

In a dry cell the zinc container acts as a negative electrode and the carbon rod as positive electrode. When conducting wires are connected to these electrodes, then current can be established in a appliance. Nowadays dry cells are used the most in gadgets etc.

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BY SCIVIBHANSHU

THANK YOU

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