Electrical Measurement Topics
1. Errors in Measurement
Errors in measurement refer to the deviation of the measured value from the true
value. These errors can be classified into three main types:
1. Gross Errors: Caused by human mistakes such as incorrect readings or recording
errors.
2. Systematic Errors: Result from flaws in the measurement system, including
instrumental and environmental errors.
3. Random Errors: Arise from unpredictable variations in measurement conditions.
Key Definitions:
- Absolute Error = Measured Value – True Value
- Relative Error = Absolute Error / True Value
- Percentage Error = (Absolute Error / True Value) × 100
Example:
True value of resistance = 100Ω, Measured value = 98Ω
- Absolute Error = 2Ω
- Relative Error = = 0.02
- Percentage Error = 2%
Likely Exam Questions:
1. Define absolute and relative error.
2. Explain three types of errors with examples.
3. A voltage is measured as 48V instead of 50V. Calculate:
- Absolute error
- Relative error
- Percentage error
2. Basic Meters and Instruments for Electrical Measurements
Key Instruments: