Physics · Unit 1 · Electrical circuits · Current, potential difference and energy flow
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A student measures the potential difference across three resistors connected in series to a 12 V battery. The potential differences recorded are 3.0 V, 4.5 V and 4.2 V respectively. What does this measurement pattern most likely indicate about the circuit?
A household appliance operates at 240 V and draws a current of 6.25 A for 48 minutes. During this time, the appliance releases 3.60 MJ of thermal energy to the surroundings. What conclusion can be drawn about the energy conversion efficiency of this appliance?
A heating element in an industrial dryer is designed to operate at \(240\) V and dissipate \(3{,}600\) W of power. During a fault, the supply voltage drops to \(180\) V. (a) Determine the resistance of the heating element. (2 marks) (b) Calculate the power dissipated by the heating element when the supply voltage is \(180\) V. (2 marks)
A 12 V battery supplies a current of 2.5 A to a resistor. What is the power dissipated by the resistor?