Measurements

Which of these is a derived unit?

• 1 Metre
• 2 Second
• 3 Kilogram
• 4 Newton

The dimensions of velocity are:

• 1 [L² T⁻¹]
• 2 [L T⁻¹]
• 3 [L T⁻²]
• 4 [M L T⁻¹]

How many significant figures are in 0.004050?

• 1 3
• 2 6
• 3 2
• 4 4

A length is measured as 2.50 m with an uncertainty of 0.05 m. The percentage uncertainty is:

• 1 0.2 percent
• 2 5 percent
• 3 0.05 percent
• 4 2 percent

Which quantity has the dimensions [M L² T⁻²]?

• 1 Pressure
• 2 Force
• 3 Energy
• 4 Power

The SI unit of luminous intensity is the:

• 1 Lux
• 2 Lumen
• 3 Candela
• 4 Watt

Which instrument gives the most precise measurement of the thickness of a thin wire?

• 1 Screw gauge
• 2 Measuring tape
• 3 Vernier calliper
• 4 Metre rule

A random error can be reduced by:

• 1 Changing the unit
• 2 Taking many readings and averaging
• 3 Using a single reading
• 4 Ignoring the zero error