An electric winch uses 1500 J of electrical energy. It provides 600 J of useful output energy in lifting a load. What is the efficiency of the winch?
4.0%4.0\%4.0%
40%40\%40%
60%60\%60%
90%90\%90%
533 exam-style questions on CIE IGCSE Physics 1.7 Energy, work and power, covering 1.7.1a Energy stores and energy transfers, 1.7.1b Conservation of energy, 1.7.1c Kinetic and gravitational potential energy, 1.7.2 Work done, 1.7.3 Energy resources, 1.7.3a Energy resources and electricity generation, 1.7.3b Nuclear fusion as an energy source, 1.7.3c Efficiency of energy transfer, and 1.7.4 Power. Each one has a worked solution and a mark scheme showing where the marks go.