P4

Question 1

Define Ohm’s Law.

Answer 1

The relationship between voltage, current, and resistance in an electrical circuit.

Question 2

Fill in the blank: Voltage is equal to _______ multiplied by resistance.

Answer 2

Current

Question 3

True or false: Ohm’s Law applies to all materials.

Answer 3

FALSE

It primarily applies to ohmic materials, which have a constant resistance.

Question 4

What is the formula for Ohm’s Law?

Answer 4

V = I × R, where V is voltage, I is current, and R is resistance.

Question 5

Define current.

Answer 5

The flow of electric charge in a circuit, measured in amperes.

Question 6

What unit measures resistance?

Answer 6

Ohms

Question 7

Fill in the blank: Resistance opposes the flow of _______.

Answer 7

Current

Question 8

True or false: Increasing resistance decreases current if voltage is constant.

Answer 8

TRUE

Question 9

What happens to current if voltage increases while resistance remains constant?

Answer 9

Current increases.

Question 10

Define voltage.

Answer 10

The electric potential difference between two points in a circuit.

Question 11

Fill in the blank: Power in an electrical circuit is calculated as _______ times voltage.

Answer 11

Current

Question 12

What is the unit of power?

Answer 12

Watts

Question 13

True or false: Ohm’s Law can be rearranged to find any variable.

Answer 13

TRUE

Question 14

What does a resistor do in a circuit?

Answer 14

It limits the flow of current.

Question 15

Fill in the blank: Ohmic materials have a _______ resistance.

Answer 15

Constant

Question 16

What is the effect of temperature on resistance?

Answer 16

Resistance typically increases with temperature in conductors.

Question 17

Fill in the blank: In a series circuit, total resistance is the _______ of individual resistances.

Answer 17

Sum

Question 18

What is the relationship between voltage and current in a series circuit?

Answer 18

Voltage divides among components, while current remains constant.

Question 19

Fill in the blank: In a parallel circuit, voltage is _______ across all branches.

Answer 19

Equal

Question 20

What happens to total resistance in a parallel circuit?

Answer 20

Total resistance decreases as more branches are added.

Question 21

Define resistance in physics.

Answer 21

The opposition to the flow of electric current, measured in ohms.

Question 22

What causes electrical resistance in materials?

Answer 22

Factors include temperature, material type, and physical dimensions.

Question 23

True or false: Higher temperatures generally increase resistance in conductors.

Answer 23

TRUE

Increased thermal energy causes more collisions among charge carriers.

Question 24

Fill in the blank: Resistivity is a property that quantifies a material’s ______ to electric current.

Answer 24

resistance

Question 25

What is the **effect of length** on resistance?

Answer 25

Resistance increases with the length of the conductor.

Question 26

Define **Ohm's Law**.

Answer 26

The relationship between voltage, current, and resistance: V = I × R.

Question 27

True or false: **All materials** have the same resistance.

Answer 27

FALSE ## Footnote Different materials have varying resistivity values.

Question 28

What happens to resistance in a **series circuit**?

Answer 28

Total resistance is the sum of individual resistances.

Question 29

Fill in the blank: **Conductors** have ______ resistance compared to insulators.

Answer 29

low

Question 30

What is **skin effect**?

Answer 30

The tendency of alternating current to flow near the surface of conductors.

Question 31

Define **series circuit**.

Answer 31

A circuit where components are connected end-to-end, so current flows through each component.

Question 32

Define **parallel circuit**.

Answer 32

A circuit where components are connected across common points, allowing multiple paths for current.

Question 33

True or false: In a **series circuit**, if one component fails, the entire circuit stops working.

Answer 33

TRUE ## Footnote This is due to the single path for current flow.

Question 34

Fill in the blank: In a **parallel circuit**, voltage is ______ across all components.

Answer 34

the same

Question 35

What is the main advantage of a **parallel circuit**?

Answer 35

If one component fails, others can still function, maintaining circuit operation.

Question 36

What happens to total resistance in a **series circuit**?

Answer 36

Total resistance increases as more components are added.

Question 37

What happens to total resistance in a **parallel circuit**?

Answer 37

Total resistance decreases as more components are added.

Question 38

True or false: **Series circuits** are used in Christmas lights.

Answer 38

TRUE ## Footnote A failure in one bulb can cause all lights to go out.

Question 39

Define **short circuit**.

Answer 39

An unintended path that allows current to flow with little or no resistance.

Question 40

Fill in the blank: A **circuit breaker** is used to prevent ______.

Answer 40

overcurrent

Question 41

What is a **combination circuit**?

Answer 41

A circuit that includes both series and parallel components.

Question 42

True or false: **Voltage** is the same across components in a series circuit.

Answer 42

FALSE ## Footnote Voltage divides among components based on their resistance.

Question 43

What is the role of a **resistor** in a circuit?

Answer 43

To limit the flow of electric current.

Question 44

Fill in the blank: **Ohm's Law** states that voltage equals ______ times current.

Answer 44

resistance

Question 45

Define **current**.

Answer 45

The flow of electric charge, measured in amperes.

Question 46

What is the unit of **voltage**?

Answer 46

Volt

Question 47

True or false: **Capacitors** store electric charge.

Answer 47

TRUE ## Footnote They release energy when needed in a circuit.

Question 48

What is the function of a **diode**?

Answer 48

To allow current to flow in one direction only.

Question 49

Fill in the blank: A **transformer** is used to change ______ levels.

Answer 49

voltage

Question 50

What is a **fuse**?

Answer 50

A safety device that breaks the circuit when current exceeds a certain level.