Show that the equivalent resistance of a parallel combination is less than any one of the resistances.

Important Questions on Electric Resistance and Ohm's Law

MEDIUM

12th ICSE

IMPORTANT

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

Define drift velocity, time of relaxation and current density. Current density is a vector quantity but current has both magnitude and direction still it is considered as scalar. Why?

HARD

12th ICSE

IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 2

State Ohm’s law. Derive it on the basis of drift velocity, time of relaxation and collisions of free electrons with ions of a metallic substance.

HARD

12th ICSE

IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 3

Define electric resistance, specific resistance and specific conductance. Write the factors on which electric resistance depends.

HARD

12th ICSE

IMPORTANT

NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 4

Write vector form of Ohm' law universal? Show graphically ohmic and-ohmic nature of the conductors, giving examples of each.

HARD

12th ICSE

IMPORTANT

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

Explain resistivity, show its variation with temperature for

(i) conductors (ii) semi-conductors (iii) alloys.

HARD

12th ICSE

IMPORTANT

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

Define and write units of specific resistance and specific conductance. Some mass of a metal wire is drawn in two wires in such a way that second one is double in thickness. Compare the resistances.

HARD

12th ICSE

IMPORTANT

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

Show that effective resistance in series combination increases. While that in parallel combination decreases. Two wires of iron and copper of same dimensions are connected in series. The iron wire burns out but the copper wire not even visible glow.Explain.

HARD

12th ICSE

IMPORTANT

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

A current of