Q1 of 72 Page 12

Calculate the work done in moving a charge of 5 coulombs from a point at 20 to another at 30 V.

Given;

Charge (Q) = 5C;


Potential difference = 30 – 20 = 10V;


Work done = Charge × Potential difference


⇒ Work done = 5 × 10 = 50 J.


Hence the work done is 50 Joule.

More from this chapter

All 72 →
43 The value of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor are given below:
I (amperes) 0.5 1.0 2.0 3.0 4.0
V (volt) 0.5 2.5 6.75 11.0 15.0. 44 Calculate the resistance of one metre of copper wire that has a cross–sectional area of about 2 x 10-2 cm2 (using the value of resistivity of copper to be 1.2 × 10-8 ohm m) Compare the value of this resistance with that of a flashlight bulb, which has a power rating of 1 W and operates at 3 V. What does this comparison tell you ? 2

Define the unit of current.

 3

What is electric potential?