A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 5 - Current Electricity>EXERCISE 5>Q 62

EASY

12th West Bengal Board

IMPORTANT

Earn 100

A cell of emf $(ε)$ and internal resistance $(r)$ is connected across a variable external resistance $(R)$ . Plot graph to show terminal potential difference of the cell with $R$ .

Important Questions on Current Electricity

HARD

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 5 - Current Electricity>EXERCISE 5>Q 1

State and explain Ohm's law. Write the names of the units of resistance and resistivity.

MEDIUM

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 5 - Current Electricity>EXERCISE 5>Q 2

Find the equivalent resistance of three resistances

R_{1}

,

R_{2}

and

R_{3}

joined in

(i)

in series and

MEDIUM

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 5 - Current Electricity>EXERCISE 5>Q 2

(ii) Find the equivalent resistance of three resistances

R_{1}

,

R_{2}

and

R_{3}

joined in parallel.

HARD

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 5 - Current Electricity>EXERCISE 5>Q 3

Find the condition in which a larger number of cells joined in a mixed combination gives the maximum current in an electric circuit.

HARD

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 5 - Current Electricity>EXERCISE 5>Q 4

Draw the circuit diagram and explain how $\mathrm{Ohm}$ 's law may be verified in the laboratory.

HARD

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 5 - Current Electricity>EXERCISE 5>Q 5

Two cells of unequal emf

E_{1}

and

E_{2}

and internal resistance

r_{1}

and

r_{2}

are joined in parallel and sends the current to an external resistance

R

. Find the current sent by each cell and the total current. Also find the equivalent emf and equivalent internal resistance.

HARD

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 5 - Current Electricity>EXERCISE 5>Q 6

How does resistance of a metal wire depend on temperature? Define temperature co-efficient of resistance and mention its unit.

HARD

12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 5 - Current Electricity>EXERCISE 5>Q 7

Write down Kirchhoff's law relating currents and potential drops in complex electric circuit.