Question

Calculate the efficiency in percent (rounded off to 1 decimal place) of an oil expeller which yields 37 kg oil containing 5% solid impurities from 100 kg mustard seeds. The oil content of the mustard seed is 38%.

Hint:

When impurities are mentioned, always correct the yield to obtain the actual pure oil yield before computing efficiency.

Answer 1

Correct Answer: 92

Step 1: Calculate theoretical maximum oil content.
Given mustard seeds = 100 kg. Oil content = 38%. \[ \text{Theoretical oil} = 100 \times 0.38 = 38 \ \text{kg} \]
Step 2: Correct the actual oil yield.
Actual yield reported = 37 kg of crude oil. But this contains 5% impurities. \[ \text{Pure oil obtained} = 37 \times (1 - 0.05) = 37 \times 0.95 = 35.15 \ \text{kg} \]
Step 3: Calculate efficiency.
\[ \eta = \frac{\text{Actual oil obtained}}{\text{Theoretical oil}} \times 100 = \frac{35.15}{38} \times 100 = 92.5% \] Rounded to 1 decimal place: 92.5%. Final Answer: \[ \boxed{92.5%} \]