Can someone help me figure out questions 6 and 7? im learning physics.

enter image source here

1 Answer
Apr 11, 2018

#6#: A, #7#: A.

Explanation:

We have to assume that the 3 bulbs are equal and the 2 voltage sources are equal. It would be unfair otherwise, sorry, but I am generally suspicious.

#6#. The answer is given and the brief explanation is OK.

The next question's explanation should make it more clear.

#7#. With 2 bulbs in series, circuit B has twice as much resistance. Since
#"current" = "voltage"/"resistance"#,
the circuit with less resistance will have more current.

The question did not ask for this, but here is some extra discussion: Since
#"power" = "current"^2*"resistance"#.
the circuit with higher current will use energy faster -- meaning it will give more light energy. In fact, the one bulb in A will provide more light energy than the total provided by the 2 bulbs in B.

I hope this helps,
Steve