IGS Ph Potential Dividers

The PD across R1 is 10 V. What's the PD across R2?

• 12 V

• 6 V

• 4 V

• 2 V

Why must the PD across R2 be 2 V?

• The supply PD is shared between the resistors in series.

• Energy is conserved and the PD between two points is related to the energy gained/lost by charge moving between those points.

• 12 - 10 = 2

• The current through R2 must be one fifth of the current through R1

What's the potential difference across the 40 ohm resistor?

• 12 V

• 8 V

• 6 V

• 4 V

What's the potential difference across the 80 ohm resistor?

• 12 V

• 8 V

• 6 V

• 4 V

How does the PD across R1 (40Ω) compare to the PD acros R3 (1kΩ)?

• The PD across R1 is the greater.

• R1 & R3 have the same PD across them.

• The PD across R1 is the lesser.

• It's not possible to compare them.

The two circuits shown have differing power supplies.

How does the PD across R1 compare to the PD across R3?

• The PD across R1 is the greater.

• R1 & R3 have the same PD across them.

• The PD across R1 is the lesser.

• It's not possible to compare them.

The resistance of the variable resistor is increased from 2 kΩ to 5 kΩ.

During the resistance increase, what happens to the PD across the variable resistor?

• It increases

• It decreases

• It feels nicer

The resistance of the variable resistor is increased from 2 kΩ to 5 kΩ.

During the resistance increase, what happens to the PD across the R1?

• It increases

• It decreases

• It gets more yellowy

Which 1, 2 or 3 are correct?

• The PD across R1 added to the PD across the variable resistor gives 12 V

• If the PD across R1 increases then the PD across the variable resistor must decrease.

• The ratio of the PDs across the two resistors will be the same as the ratio of their resistances.

When a resistor is added in parallel to the 2 kΩ resistor, what happens to the PD across the 2 kΩ resistor?

• The PD across the 2 kΩ increases

• The PD across the 2 kΩ decreases