Electricity & D.C Circuits

Question 1

Ohm

Answer 1

Volt/ Ampere

Question 2

Equal voltage Cells connected in parallel with positives together. What happens to original voltage of the first cell ?
Does this affect resistors in the circuit?

Answer 2

-T is halved.
-no change

Question 3

Define volt

Answer 3

Volt = Joule / Coulomb

Question 4

Two lamps P and Q connected in parallel. This combination is connected in series with a resistor R and power supply of 4.5 V. I-V graph given.
1. Find current in battery.
2. Calculate the resistance of resistor R.
3. The filament wire of lamp Q breaks and stops conducting. State and explain, qualitatively, the effect on the resistance of lamp P.

Answer 4

1. I = I(p) + I (q) {from graph}
2. V = IR
   R = V across R/ I
   = ( Emf - (p.d across lamps) ) / I from part 1.