Solutions to the Quiz on Electric Circuits, Voltage, Ohm's Law, and Power

Question 1: A current of 60 mA flows through a wire for 1 minute,
Calculate the quantity of charge moved by the current during this time? Answer: 3.6 C
Explanation: Charge q = I × t and 1 C = 1 A•s, and hence q = 0.06A × 60s = 3.6 C

Question 2: An battery is used to ..................

Answer: maintain a potential difference.

Question 3: Assume a resistor R is connected across a battery of negligible internal resistance.
If the resistance of R is halved, the current in R would be..................

Answer: doubled.

Explanation: We know that current I = ε / R, and so if R is halved then I would be doubled.

Question 4: Let's consider a 9-V battery in a simple circuit generating a current of 2A through the circuit.
Calculate the power being delivered by the battery. Answer: 18 watts

Power P = ε × I and so P = 9 × 2 = 18 watts

Question 5: In the circuit shown below, which device is used to measure the electric current in the circuit?
Electric Circuit

Answer: Circuit number 1

Question 6: Assume that a student would like to measure the voltage across one of the resistors in the circuit shown above (question 5),
the student would connect a voltmeter ..........................the resistor.

Answer: in parallel with

Question 7: The resistance of a circuit element is a measure of ................

Answer: 1

Question 8: Consider a circuit where the voltage drop across a resistor is 8.0 V for a current of 2.0 A in the resistor.
Calculate the current that will generate a voltage drop of 4.0 V across the resistor.

Answer: 1 A
Explanation: We know that current I = ε / R, and so if ε is halved then I would be also halved and so equal to 1 A.

Question 9: Ohm's law tells us that the amount of current generated in a circuit is..........................

Answer: directly proportional to voltage.
Explanation: We know that current I = ε / R.

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Date of last modification: Summer , 2019