1.
What is the basic unit of voltage?
Correct Answer
B. Volts
Explanation
Voltage is the measure of electric potential difference between two points in an electrical circuit. It represents the force that drives electric current. The basic unit of voltage is the volt, which is named after the Italian physicist Alessandro Volta. Watts, coulombs, and amperes are all related to electricity, but they are not the basic unit of voltage.
2.
How should a voltmeter be placed in the circuit?
Correct Answer
B. In parallel
Explanation
A voltmeter should be placed in parallel with the circuit because it measures the potential difference across a component or set of components. Placing it in parallel ensures that it does not affect the circuit's current flow, as it has a high resistance and does not draw significant current. This allows accurate measurement of the voltage without altering the circuit's behavior.
3.
How should one place an ammeter in a circuit?
Correct Answer
A. In series
Explanation
An ammeter should be placed in series in a circuit. Placing it in series means that the ammeter is connected in line with the current flow, allowing it to measure the current passing through the circuit. This is important because an ammeter needs to be part of the current path in order to accurately measure the current. Placing it in parallel would create a short circuit, disrupting the flow of current and giving inaccurate readings. Placing it above the circuit or upside down would not allow the ammeter to be part of the current path, rendering it ineffective.
4.
What is the basic unit of an electric current?
Correct Answer
D. Amperes
Explanation
The basic unit of an electric current is Amperes. Amperes measure the rate of flow of electric charge in a circuit. It represents the number of electrons passing through a point in a circuit per second. Coulombs represent the quantity of electric charge, ohms represent the resistance, and volts represent the electric potential difference. Therefore, Amperes is the correct answer as it specifically measures the current flow.
5.
If the two resistors are in parallel with a voltage source. What happens to their voltages?
Correct Answer
B. Voltage across both resistors is the same as the source.
Explanation
When two resistors are connected in parallel with a voltage source, the voltage across both resistors is the same as the source. This is because in a parallel circuit, the voltage across each component is equal to the voltage of the source. Therefore, both resistors will have the same voltage across them.
6.
A resistor has 5 volts and a resistance of 15 ohms. Can you calculate the power consumed?
Correct Answer
D. 1.67 watts
Explanation
The power consumed by a resistor can be calculated using the formula P = V^2/R, where P is the power, V is the voltage, and R is the resistance. In this case, the voltage is given as 5 volts and the resistance is given as 15 ohms. Plugging these values into the formula, we get P = (5^2)/15 = 25/15 = 1.67 watts.
7.
A graph of plot voltage vs. current in a circuit is plotted, and a linear line is obtained. What is the significance of the slope?
Correct Answer
A. Resistance
Explanation
The slope of the linear line in a voltage vs. current graph represents the resistance in the circuit. Resistance is a measure of how much a circuit impedes the flow of current. A steeper slope indicates a higher resistance, while a shallower slope indicates a lower resistance. Therefore, the significance of the slope in this case is that it provides information about the resistance in the circuit.
8.
A resistor is seen to be consuming 5 watts, and the current flowing through it is 10 amps. What is its voltage?
Correct Answer
A. 0.5V
Explanation
The power consumed by a resistor can be calculated using the formula P = IV, where P is power, I is current, and V is voltage. In this case, the power consumed is given as 5 watts and the current flowing through the resistor is given as 10 amps. By rearranging the formula, we can solve for voltage: V = P/I. Plugging in the values, we get V = 5 watts / 10 amps = 0.5 volts.
9.
A resistor is 10 volts across it and has a current of 4 amps going through it. Calculate the resistance.
Correct Answer
A. 2.5 ohm
Explanation
The resistance can be calculated using Ohm's Law, which states that resistance (R) is equal to voltage (V) divided by current (I). In this case, the voltage across the resistor is 10 volts and the current going through it is 4 amps. Therefore, the resistance is calculated as 10 volts divided by 4 amps, which equals 2.5 ohms.
10.
A current of 3 amperes flows through the resistor of 1-ohm resistor. What is voltage?
Correct Answer
A. 3V
Explanation
The voltage can be calculated using Ohm's Law, which states that voltage (V) is equal to current (I) multiplied by resistance (R). In this case, the current is given as 3 amperes and the resistance is given as 1 ohm. Therefore, the voltage can be calculated as 3V.