Significant Figure — NEET Physics MCQs with Solutions
Free NEET Physics Significant Figure MCQs with step-by-step solutions (25 questions). Part of Units and Dimensions. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Significant Figure · easy · numerical
The number of significant figures in 2.530 is
A. 2
B. 3
C. 4 ✓ Correct
D. 5
Solution: The trailing zero after a decimal point is significant: 2, 5, 3, 0 → 4 sig figs.
Q2 — Significant Figure · easy · numerical
The number of significant figures in 0.005 is
A. 1 ✓ Correct
B. 2
C. 3
D. 4
Solution: Leading zeros are NOT significant; only the digit 5 counts → 1 sig fig.
Q3 — Significant Figure · medium · numerical
The number of significant figures in 40800 (no decimal shown) is normally taken as
A. 3 ✓ Correct
B. 2
C. 5
D. 4
Solution: Without a decimal point, trailing zeros are ambiguous and usually not counted: 4, 0, 8 → 3 sig figs.
Q4 — Significant Figure · easy · numerical
The number of significant figures in 6.032 is
A. 3
B. 4 ✓ Correct
C. 2
D. 5
Solution: Zeros between non-zero digits are significant: 6, 0, 3, 2 → 4 sig figs.
Q5 — Significant Figure · easy · theory
Leading zeros in a number are
A. Significant only after a decimal
B. Always significant
C. Never significant ✓ Correct
D. Significant if there are two of them
Solution: Leading zeros merely fix the decimal position and are never significant.
Q6 — Significant Figure · easy · numerical
The number 100.0 has how many significant figures?
A. 1
B. 3
C. 4 ✓ Correct
D. 2
Solution: The decimal point makes all zeros significant: 1, 0, 0, 0 → 4 sig figs.
Q7 — Significant Figure · easy · theory
When multiplying or dividing, the result should have significant figures equal to
A. Always three
B. The sum of significant figures
C. The most significant figures
D. That of the factor with the FEWEST significant figures ✓ Correct
Solution: The precision of a product/quotient is limited by the least precise factor.
Q8 — Significant Figure · easy · numerical
The product 2.5 × 3.42 rounded to the correct number of significant figures is
A. 9
B. 8.550
C. 8.6 ✓ Correct
D. 8.55
Solution: 2.5 has 2 sig figs (the fewest), so the answer 8.55 rounds to 8.6.
Q9 — Significant Figure · easy · theory
When adding or subtracting, the result is rounded to the
A. Least number of DECIMAL PLACES among the terms ✓ Correct
B. Least number of significant figures
C. Most decimal places
D. Nearest whole number
Solution: Addition/subtraction is governed by decimal places, not significant figures.
Q10 — Significant Figure · easy · numerical
The sum 2.5 + 1.24 + 0.003, to the correct number of decimal places, is
A. 3.700
B. 3.7 ✓ Correct
C. 3.743
D. 3.74
Solution: 2.5 has only 1 decimal place, so the sum 3.743 rounds to 3.7.
Q11 — Significant Figure · easy · numerical
The number 0.000560 has how many significant figures?
A. 4
B. 6
C. 3 ✓ Correct
D. 2
Solution: Leading zeros do not count; 5, 6, and the trailing 0 do → 3 sig figs.
Q12 — Significant Figure · easy · numerical
Rounding 3.65 to 2 significant figures (round-half-to-even convention) gives
A. 3.6 ✓ Correct
B. 3.65
C. 3.7
D. 4.0
Solution: With the "round to even" rule, 3.65 → 3.6 (6 is already even).
Q13 — Significant Figure · easy · numerical
Rounding 4.735 to 3 significant figures (round-half-to-even) gives
A. 4.74 ✓ Correct
B. 4.73
C. 4.8
D. 4.7
Solution: The digit before the 5 is 3 (odd), so it rounds up to 4 → 4.74.
Q14 — Significant Figure · easy · theory
Exact numbers (like counting 5 apples, or the 2 in 2πr) have
A. Two significant figures
B. Zero significant figures
C. One significant figure
D. Infinite significant figures ✓ Correct
Solution: Exact/defined numbers carry infinite significant figures and do not limit precision.
Q15 — Significant Figure · easy · numerical
The radius of a wire is measured as 0.24 mm. Its significant figures are
A. 1
B. 3
C. 4
D. 2 ✓ Correct
Solution: Leading zero does not count; 2 and 4 do → 2 sig figs.
Q16 — Significant Figure · easy · theory
Significant figures represent
A. The number of decimal places
B. Only the whole-number part
C. The number of zeros
D. The reliable digits plus one uncertain digit in a measurement ✓ Correct
Solution: They express the precision: all certain digits and the first uncertain one.
Q17 — Significant Figure · easy · numerical
The number 6.320×10⁻⁵ has how many significant figures?
A. 9
B. 4 ✓ Correct
C. 5
D. 3
Solution: Only the mantissa 6.320 counts → 4 sig figs.
Q18 — Significant Figure · medium · theory
Trailing zeros in a number WITH a decimal point are
A. Significant ✓ Correct
B. Significant only if there are three
C. Ambiguous
D. Never significant
Solution: A decimal point makes trailing zeros meaningful, hence significant (e.g. 2.50 has 3 sig figs).
Q19 — Significant Figure · easy · numerical
The value 12.0 has significant figures
A. 4
B. 2
C. 1
D. 3 ✓ Correct
Solution: The trailing zero after the decimal is significant → 1, 2, 0 = 3 sig figs.
Q20 — Significant Figure · easy · numerical
A length is 5.00 cm and a width is 2.0 cm. Their product (area), to correct significant figures, is
A. 10.00 cm²
B. 10.0 cm²
C. 10.000 cm²
D. 10 cm² ✓ Correct
Solution: 2.0 has 2 sig figs, so 10.0 rounds to 10 (2 sig figs).
Q21 — Significant Figure · easy · numerical
How many significant figures are in the measurement 0.07080 kg?
A. 2
B. 3
C. 5
D. 4 ✓ Correct
Solution: Leading zeros excluded; 7, 0, 8, 0 (the trailing zero counts) → 4 sig figs.
Q22 — Significant Figure · easy · numerical
Rounding 2.746 to two significant figures gives
A. 2.7 ✓ Correct
B. 3.0
C. 2.75
D. 2.8
Solution: The third digit is 4 (< 5), so round down → 2.7.
Q23 — Significant Figure · easy · numerical
The result of 100 ÷ 3 kept to 3 significant figures is
A. 33.3 ✓ Correct
B. 33.33
C. 33
D. 33.333
Solution: To 3 sig figs, 33.333… rounds to 33.3.
Q24 — Significant Figure · easy · numerical
The mass of an object is 4.11 g and it is broken into two pieces of 2.05 g and 2.06 g. The number of significant figures in each measurement is
A. 3 ✓ Correct
B. 4
C. 1
D. 2
Solution: Each value (4.11, 2.05, 2.06) has 3 significant figures.
Q25 — Significant Figure · medium · theory
Changing the unit of a measured quantity (e.g. cm to m)
A. Does not change the number of significant figures ✓ Correct
B. Removes all zeros
C. Increases the significant figures
D. Decreases the significant figures
Solution: Significant figures reflect the measurement's precision, which does not depend on the unit chosen.