PHYSICS for Joint Entrance Examination JEE (Advanced) Electrostatics and Current Electricity>Chapter 7 - Heating Effects of Current>Exercise>Q 15

MEDIUM

JEE Advanced

IMPORTANT

Earn 100

A $20 V$ battery with an internal resistance of $5 Ω$ is connected to a resistor of $x Ω$ . If an additional $6 Ω$ resistor is connected across the battery, find the value of $x$ in $Ω$ , so that external power supplied by the battery remains the same.

Important Questions on Heating Effects of Current

EASY

JEE Advanced

IMPORTANT

PHYSICS for Joint Entrance Examination JEE (Advanced) Electrostatics and Current Electricity>Chapter 7 - Heating Effects of Current>Archives>Q 1

Two electric bulbs marked

25 W - 220 V

and

100 W - 220 V

are connected in series to a

440 V

supply. Which of the bulbs will fuse?

MEDIUM

JEE Advanced

IMPORTANT

PHYSICS for Joint Entrance Examination JEE (Advanced) Electrostatics and Current Electricity>Chapter 7 - Heating Effects of Current>Archives>Q 2

The supply voltage to a room is

120 V

. The resistance of the lead wires is

6 Ω

. A

60 W

bulb is already switched on. What is the decrease of voltage across the bulb, when a

240 W

heater is switched on in parallel to the bulb?

EASY

JEE Advanced

IMPORTANT

PHYSICS for Joint Entrance Examination JEE (Advanced) Electrostatics and Current Electricity>Chapter 7 - Heating Effects of Current>Archives>Q 3

In a large building, there are

15

bulbs of

40 W

,

5

bulbs of

100 W

,

5

fans of

80 W

and

1

heater of

1 kW

. The voltage of the electric mains is

220 V

. The minimum capacity of the main fuse of the building will be

EASY

JEE Advanced

IMPORTANT

PHYSICS for Joint Entrance Examination JEE (Advanced) Electrostatics and Current Electricity>Chapter 7 - Heating Effects of Current>Archives>Q 1

Incandescent bulbs are designed by keeping in mind that the resistance of the filament increases with the increase in temperature. If at room temperature,

100 W, 60 W,

and

40 W

bulbs have filament resistances

R_{100}, R_{60},

and

R_{40},

respectively, the relation between these resistances is

HARD

JEE Advanced

IMPORTANT

PHYSICS for Joint Entrance Examination JEE (Advanced) Electrostatics and Current Electricity>Chapter 7 - Heating Effects of Current>Archives>Q 2

For the circuit shown in the figure,

Question Image

HARD

JEE Advanced

IMPORTANT

PHYSICS for Joint Entrance Examination JEE (Advanced) Electrostatics and Current Electricity>Chapter 7 - Heating Effects of Current>Archives>Q 1

The heater of an electric kettle is made of a wire of length

L

and diameter

d

. It takes

4 minutes

to raise the temperature of

0.5 kg

water by

40 K

. This heater is replaced by a new heater having two wires of the same material, each of length

L

and diameter

2 d

. The way these wires are connected is given in the options. How much time in minutes will it take to raise the temperature of the same amount of water by

40 K

?