Metal sphere a has a charge of -q. an identical metal sphere b has a charge of 2q. the magnitude of the electric force on b due to a is f. the magnitude of the electric force on a due to b must be(a) 2f(b) f/4(c) f/2(d) f(e) 4f

option D ) is correct.

Explanation:

When two charges Q₁ and Q₂ which are unequal in magnitude as well as in nature are at a distance of R then a force F is created between them which is given by the expression

 F = k ( Q₁ X Q₂) / R²

This force acts equally on both the charges Q₁ and Q₂ irrespective of the fact that they are unequal charges . In other words both Q₁ and Q₂ experience same force F whose value is given above.

In the given case too charges are unequal in magnitude and in nature . They will attract each other with equal force . So if A experiences force F , B too will experience the same force,

Hence option D ) is correct.

d is the answer i came up with

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2