In the circuit above R is a resistor whose resistance increases with an increase in temperature. L1 and L2 are identical lamps. If the temperature of R increases
Attached Figure / Diagram
A
L1 becomes brighter and L2 becomes dimmer
B
L1 becomes brighter and L2 does not change
C
L2 becomes dimmer and L1 does not change
D
L1 becomes dimmer and L2 does not change
E
L1 and L2 becomes brighter
Verified Correct Answer: E.
Physical Principles & Numerical Solution
L2 is in series with the resistor while L1 is in parallel to the resistor, therefore both L1 and L2 will become brighter.
in series connection high resistance produces a brighter glow while in parallel connection lower resistance produces a brighter glow.
Source: Myschool Past Questions Archive (Record #33435)