Ohm’s law may also be stated by the equation j ⇀ = σ E ⇀ . What do the symbols j ⇀ , σ and E ⇀ stand for? Show that the combination of units on the two sides are identical.

Formula used: ȷ → = σ E → Here, j → = Current density ( j → = I / A ) σ = Electrical conductivity E → = Electric field. S.I. unit of j = A / m 2 S.I. unit of σ = ( − Ωm ) − 1 S.I. unit of E = V / m . then values in Eq, J = σE A m 2 = ( Ωm ) - 1 V m A m 2 = V ⋅ Ω m 2 A m 2 = A m 2

Ohm’s law may also be stated by the equation j ⇀ = σ E ⇀ . What do the symbols j ⇀ , σ and E ⇀ stand for? Show that the combination of units on the two sides are identical.

Formula used: ȷ → = σ E → Here, j → = Current density ( j → = I / A ) σ = Electrical conductivity E → = Electric field. S.I. unit of j = A / m 2 S.I. unit of σ = ( − Ωm ) − 1 S.I. unit of E = V / m . then values in Eq, J = σE A m 2 = ( Ωm ) - 1 V m A m 2 = V ⋅ Ω m 2 A m 2 = A m 2

E M B I B E

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

HARD

12th ICSE

IMPORTANT

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Ohm’s law may also be stated by the equation $\overset{⇀}{j} = σ \overset{⇀}{E}$ . What do the symbols $\overset{⇀}{j}$ , $σ$ and $\overset{⇀}{E}$ stand for? Show that the combination of units on the two sides are identical.

Important Questions on Electric Resistance and Ohm's Law

EASY

12th ICSE

IMPORTANT

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

Define resistivity of a conductor. Explain the variation of resistance with temperature in metallic wire.

MEDIUM

12th ICSE

IMPORTANT

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

Define resistivity of a conductor. Explain the variation of resistance with temperature in a piece of carbon.

HARD

12th ICSE

IMPORTANT

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

Write down a simple relationship to show the variation of resistance with temperature. Define temperature coefficient of resistance. In what way the temperature coefficient of carbon is different from that of common conductors?

HARD

12th ICSE

IMPORTANT

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

Explain energy transfer in electric circuits. Prove that the energy liberated from an electric circuit is given by