Consider the circuit below which is operated for a total time of 5 minutes and 20 seconds.
If a constant 750 mA of current flows through the circuit, how many electrons will move through the battery while the circuit is operating? (3 marks).
b. What amount of EMF is provided by the battery if 2.16 kJ of energy is supplied to the current? (2 marks).
c. What amount of power is dissipated by the light bulb? (2 marks).
d. Determine the resistance of the bulb. (1 mark).
e. If the wire inside the bulb has a radius of 0.03 mm and is 60 cm long, what material is the wire likely to be made of? .
f. Explain why the value of ρ for a given material does not remain constant with temperature. (2 marks).
2. Elec has set up the circuit below to take measurements of current around the circuit.
a. Indicate where a voltmeter should be placed so that the potential difference across the bulb can be measured. (1 mark).
b. Elec moves the ammeter to the other side of the bulb. Predict the reading Elec will see on the ammeter and explain this result. (3 marks).
c. Elec measures the provided by the battery. Predict the value the voltmeter will display if the bulb has a resistance of 25 Ω. (2 marks).
d. Indicate on the diagram the direction in which current flows. (1 mark).
e. Explain why the charges moving in the circuit do not flow in the same direction indicated. (2 marks).
Section B – Compound Circuits.
3. Show that five 10 Ω resistors can be configured such that their effective resistance is 20 Ω. Note: all 5 resistors must be used. Support your diagram with appropriate working. (3 marks).
4. Daphne constructs the following circuit which is connected to a 6 V. A current of 15 mA is measured to be moving through the 200 Ω resistor.
a. Determine the amount of current which flows through the 50 Ω resistor. (3 marks).
b. Hence determine the effective resistance of the circuit. (2 marks).
c. Consider the resistor of Ω.
i. Determine the voltage drop across the resistor.