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Current Electricity

Question
CBSEENPH12039718
Wired Faculty App

The resistance of the series combination of two resistances is S. When they are joined in parallel through total resistance is P. If S = nP, then the minimum possible value of n is

  • 4

  • 3

  • 2

  • 1

Solution

A.

4

Let the resistance R1 and R2
So, S = R1+ R2;
straight P space equals space fraction numerator straight R subscript 1 straight R subscript 2 over denominator straight R subscript 1 plus straight R subscript 2 end fraction straight S space equals nP straight R subscript 1 space plus space straight R subscript 2 space equals space fraction numerator nR subscript 1 straight R subscript 2 over denominator straight R subscript 1 plus straight R subscript 2 end fraction left parenthesis straight R subscript 1 space plus straight R subscript 2 right parenthesis squared space equals space nR subscript 1 straight R subscript 2 If space straight R subscript 1 space equals space straight R subscript 2 comma space so space minimum space value space of space straight n space equals 4

Some More Questions From Current Electricity Chapter

What conclusion can you draw from the following observations on a resistor made of alloy manganin?

Current A

Voltage V

Current A

Voltage V

0.2

0.4

0.6

0.8

1.0

2.0

3.94

7.87

11.8

15.7

19.7

39.4

3.0

4.0

5.0

6.0

7.0

8.0

59.2

78.8

98.6

118.5

138.2

158.0

Answer the following questions:
A steady current flows in a metallic conductor of non-uniform cross-section. Which of these quantities is constant along the conductor: current, current density, electric field, drift speed?

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