1.
One ______is the p.d. across a load if the work done to bring 1 C ofpositive charge across the load is 1 J.
Correct Answer
C. Volt
Explanation
Volt is the correct answer because it is the unit of measurement for electric potential difference or voltage. It represents the amount of work done to move a unit of positive charge across a load. Therefore, the p.d. across a load is measured in volts when the work done to bring 1 C of positive charge across the load is 1 J.
2.
To transfer 2.0C of charge from point A to B (where its potentialdifference is 4.0 V) in a circuit. How much energy is needed?
Correct Answer
D. 8.0 J
Explanation
To transfer charge from point A to B, work needs to be done against the electric potential difference. The amount of work done is equal to the product of charge and potential difference. In this case, the charge is 2.0 C and the potential difference is 4.0 V. Therefore, the energy needed is 2.0 C * 4.0 V = 8.0 J.
3.
4.0 J of electrical energy is converted to thermal energy when 6.0 C ofcharges pass through a resistor. What is the potential difference across the resistor?
Correct Answer
A. 0.67V
Explanation
The potential difference across a resistor can be calculated using the formula V = E/Q, where V is the potential difference, E is the electrical energy, and Q is the charge. In this case, the electrical energy is given as 4.0 J and the charge is given as 6.0 C. Plugging these values into the formula, we get V = 4.0 J / 6.0 C = 0.67V. Therefore, the potential difference across the resistor is 0.67V.
4.
This simplified diagram represents a cyclic movement of water where there is a pump, P, to pump water up to a higher level reservoir. The water flows down to the bottom reservoir, which is then again pumped up.
Now imagine that this can represent an electric circuit.
Where is the “resistor”?
Correct Answer
C. The part where the water fall through the pipe
Explanation
The correct answer is the part where the water falls through the pipe. In an electric circuit, a resistor is a component that restricts the flow of electric current. Similarly, in the water cycle analogy, the part where the water falls through the pipe acts as a restriction or obstacle to the flow of water, similar to a resistor in an electric circuit.
5.
This simplified diagram represents a cyclic movement of water where there is a pump, P, to pump water up to a higher level reservoir. The water flows down to the bottom reservoir, which is then again pumped up.
Now imagine that this can represent an electric circuit. How would you measure the “current” of this “circuit”?
Correct Answer
A. Measure the rate of water flow
Explanation
To measure the "current" of this "circuit" represented by the cyclic movement of water, you would measure the rate of water flow. Current in an electric circuit represents the flow of electric charge, and in this analogy, the rate of water flow represents the flow of water. By measuring the rate at which the water is flowing, you can determine the "current" of this water circuit.
6.
The carriers of a current in a wire are electrons. Each electron carries 1.6 x 10^{-19}C of charge. The number of electrons per second passing any section of a wire carrying a current of 0.8 A is
Correct Answer
B. 5 x 10^18
Explanation
The current in a wire is defined as the rate of flow of charge. In this case, the current is given as 0.8 A. We know that each electron carries a charge of 1.6 x 10^-19 C. To find the number of electrons passing through a section of the wire per second, we can use the formula:
Number of electrons = Current / Charge of each electron
Number of electrons = 0.8 A / (1.6 x 10^-19 C)
Simplifying this equation, we get:
Number of electrons = 5 x 10^18
Therefore, the correct answer is 5 x 10^18.
7.
This simplified diagram represents a cyclic movement of water where there is a pump, P, to pump water up to a higher level reservoir. The water flows down to the bottom reservoir, which is then again pumped up.
Now imagine that this can represent an electric circuit.
What is analogous to the water in an electric circuit?
Correct Answer
B. Electron
Explanation
In an electric circuit, the flow of electrons is analogous to the movement of water in a cyclic water system. Just like water flows from the higher level reservoir to the bottom reservoir and then gets pumped up again, electrons flow from the negative terminal of a power source to the positive terminal, creating a continuous flow of electric current. Therefore, the correct answer is "Electron."
8.
This simplified diagram represents a cyclic movement of water where there is a pump, P, to pump water up to a higher level reservoir. The water flows down to the bottom reservoir, which is then again pumped up.
Now imagine that this can represent an electric circuit.
Identify the positive pole of the “battery” in this diagram
Correct Answer
B. The top part of the pump
Explanation
The top part of the pump can be considered as the positive pole of the "battery" in this diagram because it is responsible for pumping the water up to a higher level reservoir, which is similar to the function of a positive terminal in an electric circuit.
9.
This simplified diagram represents a cyclic movement of water where there is a pump, P, to pump water up to a higher level reservoir. The water flows down to the bottom reservoir, which is then again pumped up.
Now imagine that this can represent an electric circuit.
Which part of the diagram will represent the battery?
Correct Answer
B. The pump
Explanation
In an electric circuit, the battery is responsible for providing the electrical energy to the circuit. Similarly, in the given diagram, the pump is responsible for pumping water up to a higher level reservoir, which is equivalent to providing energy to the system. Therefore, the pump represents the battery in the diagram.
10.
For a solid conductor, what is the name of the particle that carries a chargeand hence creates current call?
Correct Answer
A. Electron
Explanation
An electron is a negatively charged particle that carries a charge and creates current in a solid conductor. It is the movement of electrons within the conductor that constitutes an electric current. Protons and neutrons do not carry a charge and therefore do not create current.
11.
Which of the following represent a light bulb?
Correct Answer
C. Iii
Explanation
Option iii represents a light bulb.
12.
Which of the following represent a light emitting diode (LED)?
Correct Answer
D. Iv
Explanation
Option iv represents a light emitting diode (LED). An LED is a semiconductor device that emits light when an electric current is passed through it. Option iv is the only option that represents a symbol commonly used to represent an LED in electronic circuit diagrams.
13.
______ is defined as the energy converted from electrical to other forms when one coulomb of electrical charge passes between the two points.
Correct Answer
B. Potential difference between any 2 points
Explanation
The correct answer is "Potential difference between any 2 points." In electrical circuits, potential difference refers to the difference in electric potential energy between two points. When one coulomb of electrical charge passes between these two points, the energy is converted from electrical to other forms. Therefore, potential difference is the correct term to describe this energy conversion.
14.
A current of 3.0 A flows through the filament of a torch bulb for half a minute. What is the amount of charge that flow through the filament during this time?
Correct Answer
D. 90 C
Explanation
During the half-minute time period, the current of 3.0 A is flowing through the filament. The amount of charge that flows through a circuit can be calculated by multiplying the current by the time. Therefore, the amount of charge that flows through the filament is 3.0 A * 30 s = 90 C.
15.
A charge of 2C takes 4s to flow from one point to another in a circuit. The magnitude of this current flow is ______A?
Correct Answer
0.5
0.5A
0.5 A
Explanation
The magnitude of the current flow is 0.5A. This can be determined by using the equation I = Q/t, where I is the current, Q is the charge, and t is the time. In this case, the charge is 2C and the time is 4s. Therefore, the current is 2C/4s = 0.5A.
16.
The diagram shows a resistor connected to a cell of e.m.f. 2.0 V
What is the current flowing through this circuit?
Correct Answer
C. 0.4 A
Explanation
The current flowing through a circuit can be determined using Ohm's Law, which states that current (I) is equal to the voltage (V) divided by the resistance (R). In this case, the circuit consists of only a resistor and a cell, so the resistance is known. Since the e.m.f. of the cell is given as 2.0 V and the current is unknown, we can use Ohm's Law to calculate the current. Since the resistance is not given, we can assume it to be 5 ohms (2.0 V / 5 ohms = 0.4 A). Therefore, the correct answer is 0.4 A.
17.
The diagram shows a resistor connected to a cell of e.m.f. 2.0 V How much thermal energy is produced in the resistor in 6.0 s?
Correct Answer
A. 4.8 J
Explanation
The thermal energy produced in the resistor can be calculated using the equation E = Pt, where E is the thermal energy, P is the power, and t is the time. Since the power is equal to the product of the current (I) and the voltage (V), P = IV. In this case, the voltage is given as 2.0 V. Since the power is also equal to the rate at which energy is transferred, the thermal energy produced can be calculated by multiplying the power by the time, E = Pt. Therefore, the thermal energy produced in the resistor in 6.0 s is 4.8 J.
18.
The diagram shows a resistor connected to a cell of e.m.f. 2.0 V
How much energy would the cell have lost durings6.0 s?
Correct Answer
A. 4.8 J
19.
Correct Answer
B. 12 000 Ω
20.
Which graph represents an ohmic conductor ?
Correct Answer
A. I
Explanation
Graph i represents an ohmic conductor because it shows a linear relationship between the current and voltage. In an ohmic conductor, the current is directly proportional to the voltage, meaning that as the voltage increases, the current also increases in a linear manner. This is indicated by the straight line on graph i. On the other hand, graphs ii, iii, and iv show non-linear relationships between current and voltage, which are not characteristic of an ohmic conductor.