An object placed on a equal-arm balance requires 12 kg to balance it. When placed on a spring scale, the scale reads 12 kg. Everything (balance, scale, set of weights and object) is now transported to the Moon where the free-fall acceleration is one-sixth that on Earth. The new readings of the balance and spring scale (respectively) are-

Options

A. 12 kg, 12 kg
B. 2 kg, 2 kg
C. 12 kg, 2 kg
D. 2 kg, 12 kg

Answer

C

Explanation

In case of equal arm balance, the weights in both the pans must be same, which is 12 kg i.e., same as that measured on earth.
In case of spring balance, the extension in the spring is directly proportional to the weight of the mass suspended.
Since gravitational pull on moon is one sixth that on earth, extension in spring, too will be one sixth hence it will weight only 2 kg at moon.