Quantities and Units Questions and Answers
Understanding Quantities and Units is a fundamental concept in Electronics and Electrical Engineering. In many aptitude questions and answers for competitive exams like GATE, ISRO, DRDO, and PSU recruitments, this topic frequently appears to test your grasp of measurement systems, SI units, and conversions. Mastering these basics helps you analyze circuits, interpret instrument readings, and solve engineering problems accurately. This collection of Quantities and Units questions with answers is designed to strengthen your foundation with clear explanations and practical examples. Students preparing for aptitude test practice online or offline can use these solved problems to enhance accuracy and speed. Download PDFs or practice online to boost your exam readiness and confidence.
Quantities and Units
1. Derived units are obtained from various combinations of
- electrical quantities
- fundamental units
- metric prefixes
- international standards
2. Which of the following metric prefixes could replace 10–9?
- Nano
- Mega
- Kilo
- Micro
3. Scientific notation is a method
- of expressing a very large number
- of expressing a very small number
- used to make calculations with large and small numbers
- All of the above
4. If you drop a 5 when rounding a number, you are using the
- round-to-even rule
- significant digit rule
- round-off rule
- retained digit rule
5. A measure of the repeatability of a measurement of some quantity is
- error
- precision
- accuracy
- significant
6. Another name for "fundamental units" is
- base units
- atoms
- the metric system
- letter symbols
7. When using the terms "accuracy" and "precision" for measurements
- "precision" implies less measurement error than "accuracy"
- "accuracy" implies less measurement error than "precision"
- "precision" measures the repeatability of a measurement
- both terms mean the same thing
8. The difference between scientific and engineering notation is
- powers of ten representation
- single vs. multiple digits before decimal point
- groupings of multiples of three digits
- All of the above
9. The number 14.8 can also be expressed as
- 1.48 × 10–1
- 1.48 × 100
- 1.48 × 101
- 1.48 × 102
10. The digits in a measured number that are known to be correct are called
- accuracy digits
- significant digits
- error digits
- precision digits