1.
What is the standard electric potential delivered in household circuits?
Correct Answer
A. 120 V
Explanation
The standard electric potential delivered in household circuits is 120 V. This is the voltage that is typically supplied by the power company to homes in order to power electrical devices and appliances. V stands for volts, which is the unit of measurement for electric potential.
2.
The difference between conventional current and the true flow of charge in a circuit is best stated by the following:
Correct Answer
C. The true flow of charge in a circuit is in the opposite direction of conventional current.
Explanation
The correct answer is that the true flow of charge in a circuit is in the opposite direction of conventional current. This means that while conventional current assumes that positive charges flow from the positive terminal to the negative terminal of a battery, the actual flow of charge is in the opposite direction, from the negative terminal to the positive terminal. This is because electrons, which carry the charge, are negatively charged and are the ones that actually move in a circuit.
3.
The image shown is the circuit symbol for a
Correct Answer
D. Resistor.
Explanation
The image shown represents the circuit symbol for a resistor. A resistor is an electrical component that limits the flow of current in a circuit. It is typically used to control the amount of current flowing through a circuit or to create a voltage drop. The symbol for a resistor is a zigzag line, which matches the image provided. Therefore, the correct answer is resistor.
4.
When sketching electrical fields around a charged object,
Correct Answer
A. Arrows are drawn from the positively charged object.
Explanation
When sketching electrical fields around a charged object, arrows are drawn from the positively charged object. This is because the direction of the electric field lines represents the direction in which a positive test charge would move if placed in the field. Since like charges repel each other, the positive test charge would move away from the positively charged object, hence the arrows are drawn away from it.
5.
A voltmeter reads _____________.
Correct Answer
D. Electric potential difference.
Explanation
A voltmeter is a device used to measure the electric potential difference between two points in an electrical circuit. It is not used to measure current, resistance, or charge directly. Therefore, the correct answer is electric potential difference.
6.
Which of the following would NOT effect resistance:
Correct Answer
E. All of the above effect resistance.
Explanation
The given question asks which of the options would not affect resistance. The correct answer states that all of the options listed (temperature, material composition, length, and cross-sectional area) do indeed affect resistance. This means that any change in temperature, material composition, length, or cross-sectional area would result in a change in resistance.
7.
All objects with a resistance obey Ohm's law.
Correct Answer
B. False
Explanation
Ohm's law states that the current flowing through a conductor is directly proportional to the voltage applied across it, and inversely proportional to the resistance of the conductor. However, not all objects with resistance obey Ohm's law. Some objects, such as diodes and transistors, have a non-linear relationship between current and voltage and therefore do not follow Ohm's law. Hence, the statement that all objects with resistance obey Ohm's law is false.
8.
A voltmeter must be placed _________ to a resistor to be used.
Correct Answer
B. In parallel
Explanation
A voltmeter must be placed in parallel to a resistor to be used because in parallel connection, the voltmeter is connected across the resistor, allowing it to measure the voltage drop across the resistor accurately. Placing the voltmeter in series would disrupt the circuit and affect the measurement of voltage.
9.
A fuse melts if the circuit it is in:
Correct Answer
A. Is drawing too much current.
Explanation
A fuse melts if the circuit it is in is drawing too much current. When the current passing through a circuit exceeds the rated capacity of the fuse, it heats up and melts, breaking the circuit and protecting it from further damage. This is a safety mechanism designed to prevent excessive current flow, which could lead to overheating, fires, or other hazards.
10.
The electric company provides a household with:
Correct Answer
B. Electric potential to charges in home circuits.
Explanation
The correct answer is "electric potential to charges in home circuits." This means that the electric company provides the necessary electric potential for charges to flow through the home circuits and power the household appliances. It does not directly provide electrons, resistance, or capacitance.
11.
A circuit has three resistors of 2 O, 6 O, and 10 O in series with a 3 V battery.A. What is the equivalent resistance?B. What is the current in the circuit?C. How much power is used by the circuit?D. How much energy is used by the circuit in 10 minutes?