Older MCQs might not have the typical A, B, C,
D
choices. They
have choices 1, 2, 3, and a combination of them is the answer. Below is the key that maps such
combinations to the answer.
A
1, 2 and 3 are correct
B
1 and 2 only are correct
C
2 and 3 only are correct
D
1 only is correct
Define efficiency as: (a) (%) efficiency = (useful energy output) / (total energy input) × 100% (b) (%) efficiency = (useful power output) / (total power input) × 100% and recall and use these equations
Describe how useful energy may be obtained, or electrical power generated, from: (a) chemical energy stored in fossil fuels (b) chemical energy stored in biofuels (c) hydroelectric resources (d) solar radiation (e) nuclear fuel (f) geothermal resources (g) wind (h) tides (i) waves in the sea including references to a boiler, turbine and generator where they are used
Sketch and interpret graphs of e.m.f. against time for simple a.c. generators and relate the position of the generator coil to the peaks, troughs and zeros of the e.m.f.
