Electric Circuits
What are delocalised electrons?
A) Electrons that are permanently fixed to a single atom.
B) Electrons found only in the nucleus of an atom.
C) Electrons that are free to move between many different atoms.
D) Electrons that have gained energy but remain in their orbit.
C) Electrons that are free to move between many different atoms.
What is the correct unit of measurement for electric current?
A) Volts (V)
B) Amperes (A)
C) Ohms (Ω)
D) Watts (W)
B) Amperes (A)
What is the correct unit of measurement for electric charge?
A) Coulombs (C)
B) Amperes (A)
C) Volts (V)
D) Joules (J)
A) Coulombs (C)
What does the resistance of a material represent?
A) The amount of electric charge the material can store.
B) The difficulty with which electric current passes through the material.
C) The total potential difference across the material.
D) The rate at which energy is transferred by the current.
B) The difficulty with which electric current passes through the material.
Which of the following formulas is given for calculating the total electrical energy (E) transferred in a circuit, if you know the current (I), potential difference (V), and the time (t)?
A) E = I x V x t
B) E = I / (V x t)
C) E = I x V / t
D) E = V / I
A) E = I x V x t
In which direction is conventional current defined as flowing in a circuit?
A) From the negative terminal towards the positive terminal.
B) From the positive terminal towards the negative terminal.
C) In the same direction as the flow of electrons.
D) It flows back and forth randomly.
B) From the positive terminal towards the negative terminal.
To correctly measure the potential difference (voltage) across a component in a circuit, how should a voltmeter be connected?
A) In parallel with the component.
B) In series with the component.
C) Directly across the battery in series.
D) It should not be connected directly into the circuit.
A) In parallel with the component.
Electric current (I) is defined as the number of Coulombs of charge (Q) that flows past a point each second (t). Which unit is used for the current (I)?
A) Volts (V)
B) Amperes (A)
C) Ohms (Ω)
D) Coulombs (C)
B) Amperes (A)
What is the correct unit of measurement for electrical resistance?
A) Volts (V)
B) Amperes (A)
C) Ohms (Ω)
D) Coulombs (C)
C) Ohms (Ω)
According to the objectives, why does electrical energy passing through wires cause the wires to heat up?
A) Electrons gain energy from the atoms in the wire.
B) Electrons collide with atoms in the wire and transfer energy to them as heat.
C) The electrons melt the atoms as they pass through.
D) The current creates friction by rubbing against the sides of the wire.
B) Electrons collide with atoms in the wire and transfer energy to them as heat.
In which direction do electrons flow in an electrical circuit?
A) From the negative terminal towards the positive terminal.
B) From the positive terminal towards the negative terminal.
C) In the opposite direction to conventional current.
D) Both A and C are correct.
D) Both A and C are correct.
How does the current behave at different points in a simple series circuit?
A) The current increases as it flows through each component.
B) The current decreases after passing through each component.
C) The current splits and is less in some parts of the circuit.
D) The current is the same at all points in the circuit.
D) The current is the same at all points in the circuit.
In the formula for calculating energy, E = Q x V, if charge (Q) is measured in Coulombs and potential difference (V) is measured in Volts, what unit is used for the energy (E)?
A) Watts (W)
B) Amperes (A)
C) Volts (V)
D) Joules (J)
D) Joules (J)
How does the resistance of a material relate to whether it is a good conductor or a good insulator?
A) Materials with lower resistance are better conductors.
B) Materials with higher resistance are better conductors.
C) Resistance is only relevant for insulating materials.
D) Resistance and conductivity are unrelated properties.
A) Materials with lower resistance are better conductors.
Which of the following actions would help to reduce the electrical resistance of a wire?
A) Making the wire longer.
B) Increasing the temperature of the wire.
C) Using a metal with a naturally higher resistance.
D) Decreasing the temperature of the wire.
D) Decreasing the temperature of the wire.
What is the defining characteristic of a series circuit?
A) There is only one path for the electric current to flow.
B) The circuit has multiple different paths for the current.
C) The voltage across each component is the same.
D) The current divides when it reaches a junction.
A) There is only one path for the electric current to flow.
In a parallel circuit, how does the potential difference (voltage) across each separate branch compare to the potential difference across the battery?
A) It is shared equally between all the branches, so each branch has less voltage than the battery.
B) It is higher across the branches furthest from the battery.
C) It is the same across each separate branch as it is across the battery.
D) It adds up across the branches to equal the battery voltage.
C) It is the same across each separate branch as it is across the battery.
The amount of electric charge (Q) that flows depends on both the current (I) and the time (t) that the current flows for. If a large current flows for a short time, and a small current flows for a long time, and they both result in the same total amount of electricity flowing, what quantity was the same in both cases?
A) The electric current.
B) The time duration.
C) The electric charge.
D) The electrical power.
C) The electric charge.
If you connect several resistors in a series circuit, how do you calculate the total resistance of the circuit?
A) You add the resistance of each individual resistor together.
B) You divide the total voltage by the total current.
C) You find the sum of the reciprocals of each resistance.
D) You average the resistance of each individual resistor.
A) You add the resistance of each individual resistor together.
Which of these factors is listed as a way to decrease the electrical resistance of a wire?
A) Using a thicker wire.
B) Using a wire made from a material with higher resistivity.
C) Increasing the voltage across the wire.
D) Passing a smaller current through the wire.
A) Using a thicker wire.
What is the defining characteristic of a parallel circuit?
A) There is only one path for the electric current to flow.
B) The circuit has multiple paths for the current to flow.
C) The total resistance is the sum of individual resistances.
D) The current is the same through all components.
B) The circuit has multiple paths for the current to flow.
What happens to the electric current from the battery when it reaches a junction where a parallel circuit splits into branches?
A) The current in each branch is the same as the current from the battery.
B) The currents in the individual branches add up to the total current from the battery.
C) The current stops flowing in the main part of the circuit.
D) The current in each branch is always less than the current in any other branch.
B) The currents in the individual branches add up to the total current from the battery.
The formula E = Q x V tells us how much energy (E) is transferred when a charge (Q) moves through a potential difference (V). Based on this formula, the amount of energy transferred by a given amount of charge is directly dependent on which other quantity?
A) The electric current flowing.
B) The resistance of the circuit.
C) The potential difference it moves across.
D) How long the charge takes to move.
C) The potential difference it moves across.
What is the primary function of a component called a 'resistor' in an electrical circuit?
A) To generate electricity for the circuit.
B) To store electrical energy.
C) To measure the potential difference across a component.
D) To have a specific resistance to control the amount of current flowing.
D) To have a specific resistance to control the amount of current flowing.
Based on the factors listed in the learning objectives that affect resistance, which of the following actions would cause the electrical resistance of a wire to increase?
A) Using a thicker wire.
B) Using a shorter wire.
C) Using a wire made from a material with a naturally lower resistance.
D) Increasing the temperature of the wire.
D) Increasing the temperature of the wire.