MCQ
Q.
If G is the gravitational constant and g is the acceleration due to gravity, the unit of G/g is
Correct Answer: D
The correct answer is option 4) i.e. kg-1 m2
CONCEPT:
- Gravitational constant, G: G is a physical constant and therefore is universal in nature and has a constant value everywhere.
- The value of G does not change with respect to time or place and is equivalent to 6.674 × 10-11 N m2 kg-2
- The SI unit of G is N m2 kg-2
- Acceleration due to gravity, g: It is the acceleration of a body due to the force exerted from the earth's gravity.
- It has a constant value of 9.8 m/s2 within the surface of Earth.
- The SI unit of g is m s-2
EXPLANATION:
The unit of G = N m2 kg-2 = (mass × acceleration)m2 kg-2 = (kg × m/s2)m2 kg-2 (∵ N is the SI unit of force)
The unit of g = m s-2
Ratio, \(\frac{G}{g} = \frac{m^3 kg^{-1 }s^{-2 }}{m s^{-2}} =\) kg-1 m2
