Edexcel A Level Physics Electricity Practice Exam
Questions with Reliable Solutions
electric current - Answer the rate of flow of charged particles
voltage - Answer a measure of the amount of energy component transfer per unit of charge passing
through it
what is the difference between potential difference & emf? - Answer - potential difference is the
electrical energy per coulomb converted to other forms
- emf is the energy per coulomb supplied to a circuit
resistance - Answer opposition to the flow of current within a conductor
Ohm's law - Answer the current through a conductor is directly proportional to the potential difference
across is, providing the temperature of the conductor remains constant
why is resistance affected by temperature? - Answer 1. an increase in temperature causes an increase in
internal kinetic energy, which means ions in the metallic lattice vibrate more vigorously
2. so delocalised electrons will be more likely to collide with the ions present in the metal, losing their
energy as they travel through, which causes an increase in resistance
Kirchoff's first law - Answer the sum of currents entering a junction is equal to the sum of currents
leaving the junction
distribution of current in series circuits - Answer I1 = I2 = I3
distribution of current in parallel circuits - Answer I total = I1 + I2 + I3
Kirchoff's second law - Answer the total emf around a series circuit is equal to the sum of the potential
differences across each component
, distribution of potential differences in a series circuit - Answer V total = V1 + V2 + V3
the total emf of a circuit is equal to the sum of the individual potential differences on each branch
(taking into account the direction of their positive and negative sides)
distribution of potential differences in a parallel circuit - Answer V1 = V2 = V3
voltage is the same on each branch
distribution of resistance in series circuits - Answer R total = R1 + R2 + R3
why is the distribution of resistance in series circuits like this? - Answer - resistors in series will have a
total potential difference across them that is the sum of their individual potential differences
- V total = V1 + V2 + V3
- resistors in series will have the same current
- I1 = I2 = I3
- V = IR so IR total = IR1 + IR2 + IR3 and I is the same for each resistor so R total = R1 + R2 + R3
distribution of resistance in parallel circuits - Answer 1 / R total = 1 / R1 + 1 / R2 + 1 / R3
why is the distribution of resistance in parallel circuits like this? - Answer - resistors in parallel will have
the same potential difference for each branch
- V1 = V2 = V3
- resistors in parallel will have a total current through them that is the sum of their individual currents
- I total = I1 + I2 + I3
- I = V / R so V / R total = V / R1 + V / R2 + V / R3 and V is the same for each resistor so 1 / R total = 1 / R1
+ 1 / R2 + 1 / R3
forward bias - Answer the direction in which the current is allowed to flow in a diode
Questions with Reliable Solutions
electric current - Answer the rate of flow of charged particles
voltage - Answer a measure of the amount of energy component transfer per unit of charge passing
through it
what is the difference between potential difference & emf? - Answer - potential difference is the
electrical energy per coulomb converted to other forms
- emf is the energy per coulomb supplied to a circuit
resistance - Answer opposition to the flow of current within a conductor
Ohm's law - Answer the current through a conductor is directly proportional to the potential difference
across is, providing the temperature of the conductor remains constant
why is resistance affected by temperature? - Answer 1. an increase in temperature causes an increase in
internal kinetic energy, which means ions in the metallic lattice vibrate more vigorously
2. so delocalised electrons will be more likely to collide with the ions present in the metal, losing their
energy as they travel through, which causes an increase in resistance
Kirchoff's first law - Answer the sum of currents entering a junction is equal to the sum of currents
leaving the junction
distribution of current in series circuits - Answer I1 = I2 = I3
distribution of current in parallel circuits - Answer I total = I1 + I2 + I3
Kirchoff's second law - Answer the total emf around a series circuit is equal to the sum of the potential
differences across each component
, distribution of potential differences in a series circuit - Answer V total = V1 + V2 + V3
the total emf of a circuit is equal to the sum of the individual potential differences on each branch
(taking into account the direction of their positive and negative sides)
distribution of potential differences in a parallel circuit - Answer V1 = V2 = V3
voltage is the same on each branch
distribution of resistance in series circuits - Answer R total = R1 + R2 + R3
why is the distribution of resistance in series circuits like this? - Answer - resistors in series will have a
total potential difference across them that is the sum of their individual potential differences
- V total = V1 + V2 + V3
- resistors in series will have the same current
- I1 = I2 = I3
- V = IR so IR total = IR1 + IR2 + IR3 and I is the same for each resistor so R total = R1 + R2 + R3
distribution of resistance in parallel circuits - Answer 1 / R total = 1 / R1 + 1 / R2 + 1 / R3
why is the distribution of resistance in parallel circuits like this? - Answer - resistors in parallel will have
the same potential difference for each branch
- V1 = V2 = V3
- resistors in parallel will have a total current through them that is the sum of their individual currents
- I total = I1 + I2 + I3
- I = V / R so V / R total = V / R1 + V / R2 + V / R3 and V is the same for each resistor so 1 / R total = 1 / R1
+ 1 / R2 + 1 / R3
forward bias - Answer the direction in which the current is allowed to flow in a diode
