EASY
12th CBSE
IMPORTANT
Earn 100

Define ionic mobility. Write its relationship with relaxation time. Give its SI unit. How does one understand the temperature dependence of resistivity of a semiconductor.

Important Questions on Current Electricity

EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 14
Define the terms (i) drift velocity, A conductor of length L is connected to a dc source of emf ε. If this conductor is replaced by another conductor of same material and same area of cross-section but of length 3L, how will the drift velocity change ?
EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 14
Define the terms (ii) relaxation time. A conductor of length L is connected to a dc source of emf ε. If this conductor is replaced by another conductor of same material and same area of cross-section but of length 3L, how will the drift velocity change ?
MEDIUM
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 15
Define relaxation time of the free electrons drifting in a conductor. How is it related to the drift velocity of free electrons ? Use this relation to deduce the expression for the electrical resistivity of the material.
MEDIUM
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 16
Define the term resistivity of a conductor. Give its SI unit. Show that the resistance of a conductor is given by
R=mlne2τA
where the symbols have their usual meanings.
EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 17
Define resistivity of a conductor. Plot a graph showing the variation of resistivity with temperature for a metallic conductor. How does one explain such a behaviour, using the mathematical expression of the resistivity of a material.
EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 18

Draw a plot showing the variation of resistivity of a conductor with the increase in temperature.

How does one explain this behaviour in terms of number density of charge carriers and the relaxation time?

EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 18

Draw a plot showing the variation of resistivity of a semiconductor, with the increase in temperature.

How does one explain this behaviour in terms of number density of charge carriers and the relaxation time?

EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 19
Define conductivity of a conductor and state its SI unit. State and explain the variation of conductivity of good conductor with temperature.