WorksheetsD. C. circuits
Total questions: 16
Worksheet time: 8mins
A student varies the variable resistor R and measures the current I and potential difference V. He plots a graph of V against I. Which is the correct answer?
gradient = e.m.f.; y-intercept = internal resistance
gradient =internal resistance; y-intercept = e.m.f.
gradient = internal resistance; y-intercept = 1/e.m.f.
gradient = 1/ e.m.f.; y-intercept = internal resistance
What is meant by the electromotive force (e.m.f.) of a cell?
the e.m.f. of a cell is the energy converted into electrical energy when unit charge passes through the cell.
the e.m.f. of a cell is the energy transferred by the cell in driving unit charge through the external resistance.
the e.m.f. of a cell is the energy transferred by the cell in driving unit charge through the internal resistance of the cell.
the e.m.f. of a cell is the amount of energy needed to bring a unit positive charge from infinity to its positive pole
The value of the external resistance R is slowly increased from zero. Which statement is correct? (Ignore any temperature effects.)
A potential difference across the external resistance decreases.
A potential difference across the internal resistance increases.
The power dissipated in r increases and then decreases.
The power dissipated in R increases and then decreases.
A high-resistance voltmeter connected across a battery reads 6.0 V. When the battery is connected in series with a lamp of resistance of 10 W, the voltmeter reading falls to 5.6 V. Which statement explains the observation?
The electromotive force (e.m.f.) of the battery decreases because more work is done across its internal resistance.
The e.m.f. of the battery decreases because work is done across the lamp.
The potential difference (p.d.) across the battery decreases because more work is done across it internal resistance.
The p.d. across the battery decreases because work is done across the lamp.
A source of e.m.f. of 9.0 mV has an internal resistance of 6.0 Ω . It is connected across a galvanometer of resistance 30 Ω. What will be the current in the galvanometer?
250 μA
300 μA
1.5 mA
2.5 mA
A power supply of electromotive force (e.m.f.) 12 V and internal resistance 2.0 Ω is connected in series with a load resistor. The value of the load resistor is varied from 0.5 Ω to 4 Ω. Which graph shows how the power P dissipated in the load resistor varies with the resistance of the load resistor?
A
B
C
D
The sum of the electrical currents into a point in a circuit is equal to the sum of the currents out of the point. Which of the following is correct?
This is Kirchhoff’s first law, which results from conservation of charge.
This is Kirchhoff’s first law, which results from conservation of energy.
This is Kirchhoff’s second law, which results from conservation of charge.
This is Kirchhoff’s second law, which results from conservation of energy.
Which of the following is not true for resistors in series?
the sum of p.d. across all the resistors equal to the source of e.m.f. of negligible internal resistance
the current through each resistor is the same.
the combined resistance is always greater than any individual resistance.
the p.d. across each resistor is the same.
Which of the following is incorrect for resistor in parallel?
the sum of p.d. across all the resistors equal to the source of e.m.f. of negligible internal resistance
the sum of current through each resistor is equal to the current supplied.
the combined resistance is always less than any individual resistance.
the p.d. across each resistor is the same.
The current in the external resistor is 0.50 A. What is the internal resistance r of each battery?
1.0 Ω
2.0 Ω
4.0 Ω
6.5 Ω
What is the total resistance between X and Y?
less than 1 Ω
between 1 Ω and 10 Ω
between 10 Ω and 30 Ω
40 Ω
Which equation relating the voltmeter readings must be true?
V = V1 + V2 + V3
V + V1 = V2 + V3
V3 = 2V2
V - V1 = V3
What is the value of V?
R2VoR1
R1+R2VoR1
R1+R2VoR2
R1Vo(R1+R2)
What is the e.m.f. of the cell?
0.8 V
1.0 V
1.2 V
3.3 V
A
B
C
D
A
B
C
D
