Question

If \( N_A, N_B, N_C \) are the number of significant figures in \( A = 0.001204 \) m, \( B = 43120000 \) m and \( C = 1.200 \) m respectively, then which of the following is correct?

• A. \( N_A = N_B = N_C \)
• B. \( N_A>N_B>N_C \)
• C. \( N_A<N_B<N_C \)
• D. \( N_A>N_B = N_C \)

Hint:

Significant figures include all known digits plus one estimated digit. Count carefully!

Answer 1

The Correct Option is A

- \( A = 0.001204 \) has 4 significant figures (leading zeros are not significant).
- \( B = 43120000 \) has 4 significant figures (trailing zeros without decimal are not counted beyond last non-zero digit).
- \( C = 1.200 \) has 4 significant figures (trailing zero after decimal is significant).
Hence, \( N_A = N_B = N_C = 4 \).