EASY

12th CBSE

IMPORTANT

Earn 100

Two bulbs rated $25 W$ , $220 V$ and $100 W$ , $220 V$ are connected in series to a $440 V$ supply. Show with necessary calculations which bulb if any will fuse.

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 17

Two bulbs rated

25 W

220 V

and

100 W

220 V

are connected in series to a

440 V

supply. What will happen if the two bulbs are connected in parallel to the same supply?

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 18

A servo voltage stabilizer restricts the voltage output to

220 V

\pm 1 %

. If an electric bulb rated at

220 V

100 W

is connected to it, what will be the minimum and maximum power consumed by it?

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 19

A room is lighted by

200 W

124 V

incandescent lamps fed by a generator whose output voltage is

130 V

. The connecting wires from the generator to the user are made of aluminium wire of total length

150 m

and cross‐sectional area

15 {mm}^{2}

. How many such lamps can be installed? Specific resistance of aluminium

= 2.9 \times 10^{- 8} Ω m

MEDIUM

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 20

Two wires

A

and

B

of same material and mass, have their lengths in the ratio

1 : 2

. On connecting them, one at a time to the same source of emf, the rate of heat dissipation in

B

is found to be

5 W

. What is the rate of heat dissipation in

A

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 21

An electric heater and an electric bulb are rated

500 W

220 V

and

100 W

220 V

respectively. Both are connected in series to a

220 V

d.c. mains. Calculate the power consumed by the heater.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 21

An electric heater and an electric bulb are rated

500 W

220 V

and

100 W

220 V

respectively. Both are connected in series to a

220 V

d.c. mains. Calculate the power consumed by the electric bulb.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 22

The heater coil of an electric kettle is rated as

2000 W

200 V

. How much time will it take to heat one litre of water from

20 ° C

100 ° C

, assuming that entire electric energy liberated from the heater coil is utilized for heating water? Also calculate the resistance of the coil. Density of water is

1 g {cm}^{- 3}

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Problems For Practice>Q 23

An electric kettle was marked

500 W

230 V

and was found to raise

1 kg

of water at

15 ° C

to the boiling point in

15

minutes. Calculate the heat efficiency of the kettle.

Two bulbs rated 25 W, 220 V and 100 W, 220 V are connected in series to a 440 V supply. Show with necessary calculations which bulb if any will fuse.

Important Questions on Current Electricity

Learn and Prepare for any exam you want !

Two bulbs rated $25 W$ , $220 V$ and $100 W$ , $220 V$ are connected in series to a $440 V$ supply. Show with necessary calculations which bulb if any will fuse.