Current and voltage in circuits

Question 1

What is the relationship between charge, current, and time?

Answer 1

charge = current × time

Q = I × t

Question 2

What is electric current?

Answer 2

The rate of flow of electric charge

Question 3

What is the unit of electric current?

Answer 3

Ampere (A)

Question 4

What is the charge of an electron?

Answer 4

Negative charge

Question 5

What is the definition of voltage?

Answer 5

Energy transferred per unit charge passed

Question 6

What is the unit of voltage?

Answer 6

Volt (V)

Question 7

How many joules are in one volt?

Answer 7

1 joule per coulomb

Question 8

What characterizes an electrical conductor?

Answer 8

A material through which electric current flows easily

Question 9

What characterizes an electrical insulator?

Answer 9

A material with very high resistance to electric current

Question 10

Name three examples of electrical conductors.

Answer 10

• Copper
• Steel
• Mercury

Question 11

Name three examples of electrical insulators.

Answer 11

• Rubber
• Paper
• Plastic

Question 12

What happens in a series circuit?

Answer 12

The same electric current passes through each component

Question 13

What happens in a parallel circuit?

Answer 13

The voltage across each component is the same

Question 14

What is the advantage of connecting lamps in parallel?

Answer 14

• Lamps are brighter
• Can be controlled individually
• One lamp continues working if another blows

Question 15

In a series circuit, what happens to the voltage when more components are added?

Answer 15

Each component shares the voltage, causing bulbs to become dimmer

Question 16

What is the equation for calculating voltage?

Answer 16

voltage = energy ÷ charge

Question 17

Fill in the blank: Electric current is the rate of flow of electric _______.

Answer 17

charge

Question 18

Fill in the blank: Electric charge is measured in _________.

Answer 18

coulombs

Question 19

Fill in the blank: A battery provides electrical _______.

Answer 19

energy

Question 20

What is the function of a fuse in a circuit?

Answer 20

Designed to melt and break the circuit when too much current flows

Question 21

What component measures electric current?

Answer 21

Ammeter

Question 22

What component measures voltage?

Answer 22

Voltmeter

Question 23

What is a thermistor?

Answer 23

A device whose resistance decreases with temperature

Question 24

What is a light-dependent resistor (LDR)?

Answer 24

A device whose resistance decreases with brightness

Question 25

What is a diode?

Answer 25

A component that allows current to flow in one direction

Question 26

What is the charge-current equation in words?

Answer 26

Charge equals current times time

Question 27

Calculate the charge passing through a device with a current of 500mA for 3 minutes.

Answer 27

90C

Question 28

Calculate the current when a charge of 240C flows in 80s.

Answer 28

3A

Question 29

What is meant by the term 'battery voltage'?

Answer 29

The energy provided per coulomb of charge passing through the battery

Question 30

What is the total current in a parallel circuit?

Answer 30

The sum of the currents through the separate components

Question 31

In a series circuit, how can all components be controlled?

Answer 31

Using just one switch

Question 32

What is the direction of electron flow in a circuit?

Answer 32

From the negative terminal to the positive terminal

Question 33

True or False: In a parallel circuit, if one bulb blows, the other bulbs will continue working.

Answer 33

True