Two lamps, one rated 100 W at 220 V , and the other 60 W at 220 V , are connected in parallel to the electric mains supply. What current is drawn from the line if the supply voltage is 220 V ?

Given, Rated power of first bulb, P 1 = 100 W and Rated voltage, V = 220 V Rated power of second bulb, P 2 = 60 W and Rated voltage, V = 220 V Resistance of the first lamp , R 1 = V 2 P 1 = 220 2 100 = 484 Ω Resistance of the second lamp, R 2 = V 2 P 2 = 220 2 60 = 806 . 67 Ω If these two resistors are joined in parallel, equivalent resistance, R e q = 484 × 806 . 67 484 + 806 . 67 Current drawn from the line , I = V R e q ⇒ I = 220 484 × 806 . 67 484 + 806 . 67 = 220 302 . 5 = 0 . 727 A

How much energy is given to each coulomb of charge passing through a 6 V battery?

The potential difference created by battery, ∆ V = 6 V The potential difference between two points in a circuit is defined as the energy required (or work done) in moving one coulomb of charge from one point to the other. ∆ V = W q , where W is work done by battery and q is the charge. ⇒ W = Δ V × q = 6 V × 1 C = 6 J