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Subject :NSO    Class : Class 8

Two identical light bulbs X and Y are connected in series as shown in the sketch below. How will the brightness of the bulbs change if switch S is closed?

A X-brighter, Y-dimmer
B X-dimmer, Y-brighter
C X-brighter, Y-not lit up
D X-not lit up, Y-brighter.


Ans 1:

Class : Class 6
bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb is correct as current will flow though X but I do feel that current will prefer less resistant path so D can also be correct

Ans 2:

Class : Class 7
I too am confused as current will also flow through both the bulbs when circuit is closed. It will pass through the switch first and hence lighting up bulb Y.

Ans 3:

Class : Class 8
The answer key says that X will not light up,but why?

Ans 4:

Class : Class 6
The answer should be B as it will be closed circuit

Ans 5:

Class : Class 9
yes i too did B

Ans 6:

Class : Class 8
Please explain it. I am also confused about the answer. I myself did B.

Ans 7:

Class : Class 9

Ans 8:

Class : Class 8

Ans 9:

Class : Class 9
Yess,my answer was B also

Ans 10:

Class : Class 3
Option D is correct because current prefers the path that offers less resistance. The bulb provides resistance whereas the switch when closed does not. Hence correct answer is D

Ans 11:

Class : Class 8
X will light up... I think it's incorrect....

Ans 12:

Class : Class 8
It must be B.The current finds a more direct path to Y, Making it brighter.But the current still reaches X because there is still a path. SOF Says otherwise.

Ans 13:

Class : Class 8
The answer is B

Ans 14:

Class : Class 8

Ans 15:

Class : Class 6
answer should be b because X will also lit up

Ans 16:

Class : Class 10

Ans 17:

Class : Class 8
logically it should be B but sof says otherwise. why ????

Ans 18:

Class : Class 8
answer should be B

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