Question
A lamp is to be connected in a circuit so that the potential difference (p.d.) across it can be varied from 0 to 6 V.
Which circuit would be most suitable?
Answer/Explanation
Ans: B
Question
The diagram shows two voltmeters P and Q connected to a potential divider.
The sliding connection at point X is moved towards the top of the diagram.
What happens to the reading on P and to the reading on Q?
| reading on P | reading on Q |
A | decreases | decreases |
B | decreases | increases |
C | increases | decreases |
D | increases | increases |
Answer/Explanation
Ans: B
We know that
Since both the resistance is connected in series so, the current in both the resistance is same .
So,
On reducing resistance of P , the reading across P decreases.
And since overall current increases , so reading across Q increases.