Question

What is the difference between random error and systematic error?

Short answer

The key difference between random error and systematic error is that random error is unpredictable and fluctuates erratically, averaging out as the number of measurements increases, whereas systematic error is consistent and persistent over multiple measurements, leading to a deviation from the true value that doesn't average out. Random errors can be minimized by increasing the number of measurements and employing statistical analysis, while systematic errors can be prevented by proper calibration, experimental setup, and unbiased observation.

Step-by-step solution

Define Random Error

Random error, also known as statistical error, refers to the unpredictable and erratic fluctuations in measurements that occur due to various factors like noise in the measuring equipment, environmental conditions, or the observer's slight errors. These errors can occur in both directions, either being higher or lower than the true value, and tend to average out as the number of measurements increases.

Define Systematic Error

Systematic error, also known as a bias, is a consistent and repeatable error that occurs during measurements. These errors are caused by factors like an improperly calibrated instrument, observer bias, or incorrect experimental setup. Systematic errors result in a consistent deviation from the true value and do not average out over multiple measurements.

Example of Random Error

Let's say you have a digital scale and want to measure the weight of an object. Depending on factors such as vibrations, fluctuations in power supply, or reading the display at a slight angle (parallax error), the weight might read slightly different values each time you measure the object. These fluctuations in readings are random errors.

Example of Systematic Error

Now, let's assume the same digital scale reads consistently 5 grams higher than the true weight of any object placed on it. This means the scale is improperly calibrated, leading to a systematic error of +5 grams in each measurement. No matter how many times you measure an object's weight, the scale will always read 5 grams more than it actually weighs.

Key Differences

In summary, random error is unpredictable and fluctuates erratically, averaging out as the number of measurements increases. Systematic error is consistent and persistent over multiple measurements, leading to a deviation from the true value that doesn't average out. To minimize random errors, one can increase the number of measurements and employ statistical analysis. To prevent systematic errors, proper calibration, experimental setup, and unbiased observation are needed.