Two electric heaters, A and B, transfer the same amount of useful thermal energy to warm identical blocks of metal through the same temperature rise. Heater A is more efficient than heater B.
Which statement about the heaters is correct?
The total electrical energy input of heater A is larger than that of heater B.
The total electrical energy input of heater A is smaller than that of heater B.
The thermal energy wasted by heater A is larger than that wasted by heater B.
The useful thermal energy output of heater A is larger than that of heater B.
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.