a] State Ohm's law. Write it in the form of equation and give graphical representation for it. b] An electric oven rated at 500W is connected to a 220V line and used for 2 hours daily. Calculate the cost of electric energy per month at the rate of Rs. 5 per kWh.

a] State Ohm's law. Write it in the form of equation and give graphica

1.	a] State Ohm's law. Write it in the form of equation and give graphical representation for it. b] An electric oven rated at 500W is connected to a 220V line and used for 2 hours daily. Calculate the cost of electric energy per month at the rate of Rs. 5 per kWh.
Answer» Solution :a] Ohm.s Law: Current through a conductor between TWO points is directly PROPORTIONAL to the voltage across the two points. Mathematically, `VpropI` or V = RI where R is the constant of proportionality called resistance. If a graph of current across a conductor along y-axis is plotted against the potential difference across it taken along x-axis for different values of potential difference, then, it looks as shown in the figure. The graph will be a straight line which confirms that potential difference V is directly proportional to current I according to Ohm.s law. b] Power of the oven [P] = 500 W = 0.5 kW t[time] = 2hrs E = `Pxxt=0.5xx2=1kWh` Energy consumed in 1 month = `1kWhxx30=30kWh` 1 kWh = Rs. 5 Cost for 30 DAYS = `5xx30` = Rs. 150.00