NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 6

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12th ICSE

IMPORTANT

Earn 100

Calculate the electric current density in a uniform wire connected to a battery of emf $3.5 V$ and negligible internal resistance. The resistance of the wire is $2.0 Ω$ and its area of cross-section is $0.70 \times 10^{- 6} m^{2}$ .

Important Questions on Electric Resistance and Ohm's Law

HARD

12th ICSE

IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 7

A

3.0 m

long copper wire is carrying a current of

3.0 A

. How long does it take for an electron to drift from one end of the wire to the other? The cross-sectional area of the wire is

2.0 \times 10^{- 6} m^{- 2}

and the number of conduction electrons in copper is

8.5 \times 10^{28} m^{- 3}

.

HARD

12th ICSE

IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 8

Find out the resistivity of a conductor in which a current density of

2.5 A - m^{- 2}

is found when an electric field of

15 V - m^{- 1}

is applied it.

HARD

12th ICSE

IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 9

A very small current is sent through a wire of length

15 m

and cross-sectional area

6.0 \times 10^{- 7} m^{- 2}

Its resistance is measured to be

5.0 Ω

. Find the specific resistance of the experiment. What will be the specific conductance?

HARD

12th ICSE

IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 10

What length of a wire of diameter

0.46 mm

and specific resistance

50 \times 10^{- 6}

ohm - cm

will be required to prepare a coil of

10 ohm

?

MEDIUM

12th ICSE

IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 11

The specific resistance of Nichrome is

100 μΩ - cm

. What will be the resistance of a Nichrome wire of

5 m

length and

0.01 {cm}^{2}

area of cross-section?

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12th ICSE

IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 12

A piece of copper of mass

50 g

is drawn into a wire of length

50 m

. Find the resistance of the wire. The density and the specific resistance of copper are

8.9 \times 10^{3} kg m^{- 3}

and

1.7 \times 10^{- 8} Ω - m

respectively.

HARD

12th ICSE

IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 13

A thick wire of

10 Ω

resistance is drawn into a thin wire so that its length becomes three times. Calculate its new resistance.

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12th ICSE

IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 14

A wire of resistance

32 Ω

is melted and redrawn into wire of half its original length. Find the resistance of the new wire.