# Two lamps, one rated 40 W at 220 V and the other 60 W and 220 V, are connected in parallel to the electric supply at 220 V.(a) Draw a circuit diagram to show the connections.(b)Calculate the current drawn from the electric supply.(b) Calculate the total energy consumed by the two lamps together when they operate for one hour.

(a)

(b) As the connection is in parallel.

So voltage across both the bulbs is same and is equal to 220V.
Using the Formula P=VI,We can get I as I=P/V Where:-
P= Power
I=Current
V=Voltage/Potential Difference

Current through AB i.e 40W lamp = I1 = P1/V = 40/220 A

Current through CD i.e. 60W lamp = I2 = P2/V = 60/220 A

Total current drawn from the electric supply = 40/220 + 60/220 = 0.45 A

(c)We know that Energy= Power x Time

Total Power to two bulbs together=40W+60W=100W

According to the question both of the bulbs are being operated together at 1 hour

∴ Energy= 100W x 1hr
Energy= 100Whr

We know 1Whr= 3600 Joules
∴100Whr= 3600 X 100
=360000Joules
=360kJoules

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
What is Electric Current?56 mins
Understanding Short Circuit38 mins
Ohm's Law43 mins
Factors Affecting Resistance45 mins
Quiz | Most Challenging Questions on Electricity40 mins
What is Power Rating?38 mins
Quiz | Rapid Fire Round (Electricity)44 mins
Lets Understand Fleming's Left Hand Rule39 mins
Parallel combination of resistors36 mins
Genius Quiz | Electricity - Test your Speed and Accuracy38 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses