Zero error belongs to the category of

Error in volume of a sphere is $6\%$. Error in its radius will be .......... $\%$

Two clocks are being tested against a standard clock located in a national laboratory. At $12:00:00$ noon by the standard clock,the readings of the two clocks are

Day	Clock $1$	Clock $2$
Monday	$12:00:05$	$10:15:06$
Tuesday	$12:01:15$	$10:14:59$
Wednesday	$11:59:08$	$10:15:18$
Thursday	$12:01:50$	$10:15:07$
Friday	$11:59:15$	$10:14:53$
Saturday	$12:01:30$	$10:15:24$
Sunday	$12:01:19$	$10:15:11$

If you are doing an experiment that requires precision time interval measurements,which of the two clocks will you prefer?

The errors in the measurement which arise due to unpredictable fluctuations in temperature and voltage supply are:

In an experiment,the values of refractive indices of glass were found to be $1.54, 1.53, 1.44, 1.54, 1.56$ and $1.45$ in successive measurements. The mean absolute error is:

Error in the measurement of radius of a sphere is $0.2\%$. The error in the calculated value of its volume is ......... $\%$