New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 4

EASY

12th CBSE

IMPORTANT

Earn 100

When $10$ cells in series are connected to the ends of a resistance of $59 Ω$ , the current is found to be $0.25 A$ , but when the same cells after being connected in parallel are joined to the ends of a $0.05 Ω$ , the current is $25 A$ . Calculate the internal resistance and emf of each cell.

Important Questions on Current Electricity

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 5

Find the minimum number of cells required to produce an electric current of

1.5 A

through a resistance of

30 Ω

. Given that the emf of each cell is

1.5 V

and internal resistance

10 Ω

.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 6

Two identical cells, whether joined together in series or in parallel give the same current when connected to an external resistance of $1 Ω$ . Find the internal resistance of each cell.

MEDIUM

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 7

A set of

4

cells, each of emf

2 V

and internal resistance

1.5 Ω

are connected across an external load of

10 Ω

with

2

rows,

2

cells in each branch, Calculate the current in each branch and potential difference across

10 Ω

.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 1

Calculate the current flowing through a heater rated at

2 kW

when connected to a

300 V

d.c. supply.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 2

Calculate the amount of heat produced per second (in calories), when a bulb of

100 W

-

220 V

glows assuming that only

20 %

of electric energy is converted into light.

J = 4.2 J {cal}^{- 1}

.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 3

An electric heating element to dissipate watts on

240 V

mains is to be made from nichrome ribbon

1 mm

wide and thickness

0.05 mm

. Calculate the length of the ribbon required if the resistivity of nichrome is

1.1 \times 10^{- 6} Ωm

.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 4

100 W

,

220 V

bulb is connected to

110 V

source. Calculate the power consumed by the bulb.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 5

How many electrons flow per second through an electric bulb rated

220 V

,

100 W

?