DC Circuit

What is the definition of electromotive force (e.m.f.) of a source?

• The energy per unit charge as charge moves from point A to point B

• The total energy from power supply being transferred to each of the resistors

• The total work done per unit charge when charge flows round a complete circuit

• The electrical energy converted to non-electrical energy per unit charge

What does Kirchhoff's current law (1st Law) state?

• The sum of all voltages around any closed loop in a circuit must equal zero

• Current flowing into a junction must be equal to current flowing out of it

• The total current through the whole circuit is the sum of the current through each electrical component

• The potential difference across each component adds up to the potential difference across the battery

What is the effect of internal resistance within the source of emf?

• Results in the terminal p.d. being equal to the e.m.f value

• Results in the voltage across the terminals of the source dropping as the current is drawn from it

• Results in the total resistance across the components in series being equal to the sum of each resistance

• Results in the source being 100% efficient as energy is dissipated in the internal resistance

In a series circuit, what happens to the current across each component?

• Is the same across each component

• Adds up to the potential difference across the battery

• Is less than the potential difference across the battery

• Is shared between the components

What is the terminal potential difference, Vt, a measure of?

• The energy per unit charge as charge moves from point A to point B

• The total energy from power supply being transferred to each of the resistors

• The electrical energy production over the whole circuit minus the potential difference produced in the internal resistance within the source per unit charge flowing

• The sum of all voltages around any closed loop in a circuit must equal zero

What is the formula to calculate the internal resistance, r, of a source of emf?

• V = ε - Ir

• V = IR + Ir

• V = ε - ΔV

What does the voltage quoted on the label of a source of emf represent?

• The total work done per unit charge when charge flows round a complete circuit

• The sum of all voltages around any closed loop in a circuit must equal zero

• The energy per unit charge as charge moves from point A to point B

• The voltage measured when no current is being drawn from it

What is the potential difference across each component in a parallel circuit?

• Is less than the potential difference across the battery

• Is shared between the components

• Adds up to the potential difference across the battery

• The same

What is the total resistance across the components in parallel compared to the separate resistance across the components?

• Less

• Greater

• Depends on the number of components

• Equal

What is the effect of internal resistance within the source of emf on the terminal p.d.?

• The terminal p.d. of the source is reduced by the amount of Ir

• The terminal p.d. is not affected by internal resistance

• The terminal p.d. will be equal to the e.m.f value

• The terminal p.d. will be approximately equal to the e.m.f value