OnlineCBT
Physics · UNITS AND MEASUREMENT
हिन्दीTwo physical quantities are measured as \( A = (12.9 \pm 0.1) \text{ g} \) and \( B = (7.06 \pm 0.01) \text{ g} \). The calculated difference \( (A - B) \) expressed to the correct number of decimal places and with its absolute uncertainty is:
Correct answer · Option 2
\( (5.8 \pm 0.1) \text{ g} \)
Explanation
In subtraction, the result retains as many decimal places as the number with the least decimal places (12.9 has 1 decimal place), so \( 12.9 - 7.06 = 5.84 \approx 5.8 \text{ g} \). The absolute errors add up: \( \Delta(A - B) = \Delta A + \Delta B = 0.1 + 0.01 = 0.11 \approx 0.1 \text{ g} \). Thus \( (A - B) = (5.8 \pm 0.1) \text{ g} \).
