Measuring Instruments

Question 1

Instrument

What are the instruments used to measure length?

there are 4

Answer 1

Ruler
Measuring Tape
Vernier Caliper
Micrometer Screw gauge

Question 2

Micrometer & Vernier Caliper

Range of a micrometer screw gauge & vernier caliper measure?

Answer 2

2 decimal places

ie. 0.01

Question 3

Ruler & Measuring Tape

Range of a ruler & measuring tape measure?

Answer 3

1 decimal place

ie. 0.1

Question 4

Accuracy

Define accuracy

Answer 4

How close a measured value is to a true value.

Question 5

Precision

Define Precision

Answer 5

The degree of exactness of a measurement.

Question 6

Errors

Characteristics of random errors

Answer 6

Big random errors have high accuracy of average value, high uncertainty of single measurement.

accidental

Question 7

Errors

Characteristics of systematic errors

Answer 7

Big systematic errors, good precision of measurement, low accuracy.

Has known causes

Question 8

Random vs Systematic

Repeated readings

Answer 8

-Random errors in repeated readings cannot be repeated excatly.
-Systematic errors ing reading are constantly too high & too low.

Question 9

Random vs Systematic

Correctablilty

Answer 9

-Random errors can never be eliminated but can be reduced by taking multiple readings.
- Systematic errors has know causes & can be corrected.

Question 10

Random vs Systematic

Reason/Cause

Answer 10

• Random errors are caused by experimental errors.
• Systematic errors are because of approximation, instruments used, the environment & observations.

Question 11

Random vs Systematic

What do they reduce?

Answer 11

• Random errors reduce precision
• Systematic errors reduce accuracy

Question 12

Random vs Systematic

Examples

Answer 12

• Random:
  Reaction time
• Systematic:
  Zero errors, Parallax,
  Temperature, Approximation
  errors.

Question 13

Sensitivity

What is sensitivity in an instrument?

Answer 13

The sensitivity of a measuring instrument is its ability to respond quickly to a small change in value of a measurement.

smaller the min. scale division=more sensitive the measuring instrument

Question 14

Linear vs Non-Linear Scales

What is the difference between linear and non- linear scales.

Answer 14

-Linear scales have an equal distance between divisions while non-linear scales do not