Question

While measuring the acceleration due to gravity of a simple pendulum, a student makes a positive error of 1% in the length of the pendulum, and a negative error of 3% in the value of the time period. The percentage error in the measurement of g is:
a) 2%
b) 4%
c) 7%
d) 10%

Answer 1

Answer:

g = 4π²l/T² where l = length of pendulum, T = time period of pendulum

% uncertainty in g = (% unc. of l) + 2(% unc. of T)

= 1% + 2×3%

= 7% unc. in g.

So the answer is c.

Answer 2

Answer:

% error = Δg/g ×100 = 1+(-2)(-3) = 7

answer= c