Question

In the context of accuracy of measurement and significant figures in expressing results of experiment, which of the following is/are correct?
$\left(1\right)$ Out of the two measurements $50.14cm$ and $0.00025$ ampere, the first one has greater accuracy.
$\left(2\right)$ If one travels $478km$ by rail and $397m$ by road, the total distance travelled is $478km$.

• A.
  Only $\left(2\right)$ is correct
• B.
  Both are correct
• C.
  None of them is correct
• D.
  Only $\left(1\right)$ is correct

Answer 1

The correct option is B

Both are correct
Significant figures are the number of digits in a value, that contribute to the degree of accuracy of the value.
For $50.14cm$,
The significant number $=4$
And for $0.00025$ ampere
Significant number $=2$
Hence, $50.14cm$ has greater accuracy.
Distance travel by rail $=478km$
Distance travel by road $=397km$
Total distance travelled $=478.397km$
Rounding off to significant figures, distance travelled $=478km$
Hence, both measurements are correct.