# Lesson Worksheet: Parallel Circuits Physics • 9th Grade

In this worksheet, we will practice calculating the potential difference, current, and resistance at different points within simple parallel circuits.

Q1:

The diagram shows four circuits with components connected in parallel. Which two circuits are equivalent? • A(a) and (d)
• B(c) and (d)
• C(a) and (b)
• D(b) and (c)
• E(b) and (d)

Q2:

Elizabeth sets up the circuit shown in the diagram. The current through the first ammeter, , is 5 A. What is the value of ? Give your answer to 1 decimal place. Q3: Emma sets up the circuit shown in the diagram. Each resistor has a resistance of 10 Ω.

The value of is initially 3 A. What is the value of ?

If is then closed, what happens to the value of ?

• AIt increases.
• BIt decreases.
• CIt stays the same.

With still closed, is the resistance of the circuit lower than, higher than, or the same as it was when was open?

• AThe same
• BHigher
• CLower

and are kept closed, but is opened. Does the resistance in the circuit increase, decrease, or stay the same from when all the switches were closed?

• AIt decreases.
• BIt increases.
• CIt stays the same.

Q4: A student sets up the circuit shown in the diagram. Initially, switch 1 is closed and switch 2 is open. If she opens switch 1 and closes switch 2, will the current in the circuit increase or decrease?

• BIncrease

Q5:

A student sets up the circuit shown in the diagram. Initially, the switch is open. When the student closes the switch, will the current flowing through the circuit increase or decrease? • BIncrease

Q6:

The circuit shown in the diagram consists of two resistors connected in parallel to a cell. The value of is equal to 30 A. What is the value of ? Q7:

The circuit shown in the diagram consists of two resistors connected in parallel to a cell. The value of the current given by the second ammeter, , is 3 A. What is the value of ? Q8:

A student sets up the circuit shown in the diagram. The three resistors are identical. The value of is 15 A. What is the value of ? Q9:

A student sets up the circuit shown in the diagram. The value of is 8 A and the value of is 6 A. What is the value of ?

What is the potential difference supplied by the cell to the circuit?

Q10:

The diagram shows two resistors connected in parallel to a cell. If the potential difference across the 3 Ω resistor is 18 V, what is the potential difference across the 6 Ω resistor? 