Two similar headlight lamps are connected in parallel to each other. Together, they consume 48 W from a 6 V battery. What is the resistance of each filament?

(1) 6 Ω

(2) 4 Ω

(3) 3.0 Ω

(4) 1.5 Ω

Subtopic:  Heating Effects of Current |
 81%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Two electric bulbs, rated for the same voltage, have powers of 200 W and 100 W, respectively. If their resistances are r1 and r2, respectively then :

1. r1=2r2

2. r2=2r1

3. r2=4r1

4. r1=4r2

Subtopic:  Heating Effects of Current |
 87%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

If the current in an electric bulb decreases by 0.5%, the power in the bulb decreases by approximately :

(1) 1%

(2) 2%

(3) 0.5%

(4) 0.25%

Subtopic:  Heating Effects of Current |
 73%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

An electric bulb rated for 500 W at 100 V is used in a circuit having a 200 V supply. The resistance R that must be put in series with the bulb, so that the bulb draws 500 W, is :

(1) 18 Ω

(2) 20Ω

(3) 40 Ω

(4) 700 Ω

Subtopic:  Heating Effects of Current |
 77%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

A wire, when connected to a 220 V mains supply, has power dissipation P1. Now, the wire is cut into two equal pieces, which are connected in parallel to the same supply. Power dissipation in this case is P2. Then P2:P1  is :

(1) 1

(2) 4

(3) 2

(4) 3

Subtopic:  Heating Effects of Current |
 66%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Three bulbs of 40 W, 60 W, and 100 W are connected in series with a 240 V source. Then,

(1) The potential difference will be the maximum across the 40 W bulb.

(2) The current will be the maximum in 100 W bulb.

(3) The resistance of the 40 W bulb is the minimum.

(4) The current through the 60 W bulb will be 0.1 A.

Subtopic:  Heating Effects of Current |
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

The resistance of hot tungsten filament is about 10 times the cold resistance. What will be the resistance of 100 W and 200 V lamp when not in use?

(1) 14,000 Ω

(2) 400 Ω

(3) 40 Ω

(4) 4 Ω

Subtopic:  Heating Effects of Current |
 52%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Two electric bulbs A and B are rated 60 W and 100 W, respectively. If they are connected in parallel to the same source, then,

(1) both the bulbs draw the same current

(2) bulb A draws more current than bulb B

(3) bulb B draws more current than bulb A

(4) currents drawn in the bulbs are in the ratio of their resistances

Subtopic:  Heating Effects of Current |
 73%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Figure 7.44 shows three similar lamps L1, L2 and L3 connected across a power supply. If the lamp L3 fuses, how will the light emitted by L1 and L2 change?

(1) no change

(2) brilliance of both L1 decreases and that of L2 increases

(3) brilliance of both L1 and L2 increases

(4) brilliance of both L1 and L2 decreases

Subtopic:  Heating Effects of Current |
 57%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

A factory is served by a 220 V supply line. In a circuit protected  by a fuse marked 10 A, the maximum number of 100 W lamps in parallel that can be turned on is :

1. 11 

2. 22

3. 33

4. 66

Subtopic:  Heating Effects of Current |
 85%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh