10 minutes maximum! Can you do it in 5?

 1. Which of these is a base SI quantity?

  • A. current
  • B. power
  • C. energy
  • D. acceleration

2. Which of these is a derived unit?

  • A. amp
  • B. kilogram
  • C. joule
  • D. second

3. Which of these numbers represents the prefix 'nano'?

  • A. 10-3
  • B. 10-6
  • C. 10-9
  • D. 10-12

4. 0.0004 joules can be written in millijoules (mJ) or microjoules (µJ). Which of these gives both conversions correctly?

A
Energy in mJ Energy in µJ
A
 4 400
B
 0.4 400
C
 4 40
D
 0.4 40

5. A power station has an output of 2.5 GW. This is

  • A. 2 500 W
  • B. 2 500 000 W
  • C. 25 000 000 W
  • D. 2 500 000 000 W
 power-plant

6. A coulomb has base units of

  • A. A s
  • B. A s-1
  • C. s A-1
  • D. s-1 A-1

7. A rabbit is measured running a distance of 2.5 m in 3.45 seconds. The answer for the speed should be given as

  • A. 2.5 ÷ 3.45 = 0.7246 m s-1
  • B. 2.5 ÷ 3.45 = 0.724 m s-1
  • C. 2.5 ÷ 3.45 = 0.72 m s-1
  • D. 2.5 ÷ 3.45 = 0.7 m s-1

8. The unit [kg m s-2] is the same as a

  • A. joule
  • B. kilogram
  • C. newton
  • D. volt

9. The viscous drag force Fd on a sphere falling through a fluid is given by the equation

Fd = 6πηrv

where r is the radius of the sphere, v is the velocity and η is the viscosity of the fluid.

The units of viscosity are therefore:

  • A. N m-2 s-1
  • B. N s m-2
  • C. N s-1 m-1
  • D. N m s-1

10. The speed of waves v in shallow water is found to depend on the depth of the water d, and the gravitational field strength g.

Using dimensional analysis of units, determine which of these equations connecting v, d and g is realistic.

  • A. v = d √g 
  • B. v = g √d 
  • C. v = √(gd) 
  • D. v = gd