Question 1
Two identical small spheres X and Y carry charges of +4 μC and -6 μC respectively. They are brought into contact and then separated. What will be the final charge on sphere X?
- a.+1 μC
- b.-1 μC
- c.+5 μC
- d.-5 μC
Solution
When the spheres touch, the total charge (+4 μC and -6 μC = -2 μC) is shared equally since the spheres are identical, so each gets -1 μC. The most tempting wrong answer is '+1 μC', which results from adding the charges and forgetting to divide equally between the spheres.
