David Sang and Darrell Hamilton Solutions for Chapter: Electrical Circuits, Exercise 6: Exercise 19.6

Describe what safety issue is shown in the figure.

Explain why fuse is a safety device.

State the worst case scenario for the house if the fuse is replaced with a metal foil. Explain your answer. 

Explain the operation of a trip switch.

State the sequence of events that leads to fuse melting.

Someone is operating an electric hedge cutter whilst standing on wet grass. The cable is cut by accident. Explain why it is unlikely that a fuse will save the life of the operator.

Two $12 \mathrm{V}, 40 \mathrm{W}$ lamps are connected in series and are shining with normal brightness. State what will be seen if one of the lamps is removed and replaced with a $12 \mathrm{V}, 100 \mathrm{W}$ lamp. Explain your answer. 

Draw a circuit that will only allow current to flow clockwise, allowing a user to adjust the light level at which the lamp will turn on.