Two wires each of same material and same length have 2 : 1 ratio of their radii. If the first wire has a resistance of 2 Ω then what will be the equivalent resistance of the two wires when they are connected in series ?
A 60 W- 220 V bulb is connected in series with another bulb 40 W-220 V. Which bulb will give more illuminance ?
We have the power relation P =
For a given V,
R ∝ ; R40 > R60
In series, the current remains the same.
∴ The bulb 40 W- 220 V will give more illurninance
A wire of length 5 m is stretched by 1 mm by a force of 1 N. What is the value of energy stored in the wire ?