Uncertainty

• 2.5 %

• 3.0 %

• 7.0 %

• 10.0 %

In an experiment, a radio-controlled car takes 2.50 ± 0.05 s to travel 40.0 ± 0.1 m.

What is the car’s average speed and the uncertainty in this value?

• 16 ± 1m s^-1

• 16.0 ± 0.2 m s^-1

• 16.0 ± 0.4 m s^-1

• 16.00 ± 0.36 m s^-1

• 2 %

• 3 %

• 5 %

• 6 %

An experiment is carried out to measure the resistance of a wire.

The current in the wire is (1.0 ± 0.2) A and the potential difference across the wire is (8.0 ± 0.4) V.

What is the resistance of the wire and its uncertainty?

• (8.0 ± 0.2) Ω

• (8.0 ± 0.6) Ω

• (8 ± 1) Ω

• (8 ± 2) Ω

A thermometer can be read to an accuracy of ±0.5 °C. This thermometer is used to measure a temperature rise from 40 °C to 100 °C.

What is the percentage uncertainty in the measurement of the temperature rise?

• 0.5 %

• 0.8 %

• 1.3 %

• 1.7 %

A digital caliper is used to measure the 28.50 mm width of a plastic ruler. The digital caliper reads to the nearest 0.01 mm.

What is the correct way to record this reading?

• 0.02850 ± 0.01 m

• 0.0285 ± 0.001 m

• (2.850 ± 0.001) × 10^-2 m

• (2.850 ± 0.001) × 10^-3 m

• 1.1 %

• 1.8 %

• 2.5 %

• 3.0 %

A quantity x is to be determined from the equation

x = P-Q.

P is measured as 1.27 ± 0.02 m and Q is measured as 0.83 ± 0.01 m.

What is the percentage uncertainty in x to one significant figure?

• 0.4 %

• 2 %

• 3 %

• 7 %

A micrometer screw gauge is used to measure the diameter of a small uniform steel sphere. The micrometer reading is 5.00mm ± 0.01mm.

What will be the percentage uncertainty in a calculation of the volume of the sphere, using these values?

• 0.2 %

• 0.4 %

• 0.6 %

• 1.2 %

• 4 %

• 7 %

• 8 %

• 11 %