Question

The most precise reading of the mass of an object, among the following is
a. 20 g
b. 20.0 g
c. 20.01 g
d. 20 × 100 g

Answer 1

The most precise reading of the mass of an object, among the following is..

a. 20 g

b. 20.0 g

c. 20.01 g

d. 20 × 10⁰ g

answer : option (c) 20.01 g

explanation : precision of a reading depends upon the least count of the measuring instrument.

least count of an instrument is the minimum possible measurement  by the instrument.

for example, if we have given two different readings a and b of the same thing by two different instruments A and B respectively.

if least count of a < least count of b

then a is more precise than b.

here let's find the least count of each of them.

(a) 20 g ⇒  least count = 1 g

(b) 20.0 g ⇒ least count = 0.1g

(c) 20.01 g ⇒ least count = 0.01g

(d) 20 × 10⁰ g ⇒ least count = 1g

here you see, option (c) has the lowest value of least count and hence it is the most precise reading among them.

therefore the correct option (c).

Answer 2

Answer:

option c   correct

Explanation: