Which of the following statements are true about acceleration due to gravity ?
(a) 'g' decreases in moving away from the centre if `rgtR`
(b) 'g' decreases in moving away from the centre if `rltR`
( c ) 'g' is zero at the centre of earth
(d) 'g' decreases if earth stops rotating on its axis

Explanation

Variation of g with distance : If `r gt R` then `g prop (1)/(r^(2))`
`:.` (A) is correct
If `r lt R` then `g prop r`
`:.` (B) is incorrect & ( C ) is correct variation of g with `omega,g'=g-omega^(2)R cos^(2)lambda` If `omega=0` then g will not change at poles where `cos lambda=0`.
while at other points g increases
`:.` (D) is incorrect.