4. Electricity and magnetism
A section of Physics, 5054
Listing 10 of 944 questions
A student sets up the circuit shown in . A 6.0 V 2.8 Ω 3.6 Ω X The electromotive force (e.m.f.) of the battery is 6.0 V. The resistance of the variable resistor X is set to 1.8 Ω. Determine the total resistance of the circuit, resistance = the current measured by the ammeter. current = State what is meant by the potential difference (p.d.) across a component in a circuit. Add to the symbol for a component that is measuring the p.d. across the 2.8 Ω resistor. The resistance of X is increased. Explain why the p.d. across the 2.8 Ω resistor decreases.
5054_w18_qp_21
THEORY
2018
Paper 2, Variant 1
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is the circuit diagram of a circuit set up by a student. V P The student uses three cells, each of electromotive force (e.m.f.) 1.5 V. The cells are connected in series, as shown. State the name of component P. State what is meant by the electromotive force of a cell. The student expects the reading on the voltmeter to be 4.5 V. The actual reading is 0.2 V. Suggest two reasons why the voltmeter reading is much less than 4.5 V. In the space below, draw three cells connected in parallel. State one advantage of connecting cells in parallel.
5054_s12_qp_21
THEORY
2012
Paper 2, Variant 1
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Measurements are made of the current in a metal wire and the potential difference (p.d.) across it. shows a graph of the current against the p.d. for the wire. 0.1 0.2 0.3 0.4 current / A 0.5 p.d. / V State the relationship between the current and the p.d. for the metal wire. State how the graph shows that the temperature of the wire does not change in the experiment. Another wire of the same material has the same length as the original wire but has only half the cross-sectional area. 1. Compare the resistance of the new wire and the original wire. 2. On , draw the graph for the new wire. Three resistors are connected to a d.c. power supply, as shown in . The electromotive force (e.m.f.) of the power supply is 6.0 V. 6.0 V 24 Ω 20 Ω 80 Ω Calculate 1. the total resistance of the circuit, resistance = 2. the current supplied by the power supply, current = 3. the p.d. across the 20 Ω resistor. p.d. = The d.c. power supply is a battery that contains a number of cells. Each cell has an electromotive force (e.m.f.) of 1.5 V. 1. State what is meant by the electromotive force (e.m.f.) of a cell. 2. In the space below, draw a diagram to show how four of these cells are connected to make a battery of e.m.f. 6.0 V. Mark the positive terminal of the battery. 3. In another arrangement to produce a battery of e.m.f. 6.0 V, eight cells of e.m.f. 1.5 V are connected. In this arrangement, some cells are connected in series and some in parallel. In the space below, draw a diagram to show how the eight cells are connected to make the battery. State one advantage of using a battery made from cells in parallel rather than a single cell.
5054_s17_qp_22
THEORY
2017
Paper 2, Variant 2
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Questions Discovered
944