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Current Electricity Homework (NAT5) 1. A battery pushes 120C of charge through a circuit in 2 minutes. What is the size of the electric current in amps? (2) 2. The following passage is taken from NASA research into lightning: “Lightning is the effect of static electricity build-up within a thunderstorm cloud system. It is a giant electrical spark that can have a peak current flow greater that 200,000 amperes during a period of a few microseconds. Thunder results from the sudden heating of the air to about 20,000°C by the flow of current along a narrow channel. This flow can be from cloud to ground with several individual strokes separated by a tenth of a second. Or it can be from cloud to cloud strokes which illuminate the cloud. Strokes can also be from cloud through an aircraft or aerospace vehicle operating in the vicinity.” (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19990009077_1998432277.pdf) a) How much charge would flow if a lightning bolt carrying a current of 200,000 amps travelled from cloud to ground in 0.1 seconds. (2) b) If the cloud to ground distance was 15km and the time for the lightning bolt to reach the ground was 0.1s, calculate the speed of the lightning bolt. 3. A single cell has a voltage of 1.5V State clearly what this means. (2) (2) 4. Read the following 2 statements: Voltage is a measure of the energy delivered to each coulomb of charge. Current is a measure of the number of coulombs flowing per second. A 9V battery delivers a current of 3A to a lamp. How much energy is delivered to the lamp every second? (2) (10 marks)