Current, Voltage and resistence

Question 1

How do you calculate current?

Answer 1

Current in amps = charge in coulumbs

time in seconds

Question 2

What is the current if 20 C of charge passes in 5 s?

Answer 2

4A

Question 3

What is potential difference measured in?

Answer 3

Volts or V

Question 4

How do you measure the potential difference in a circuit?

Answer 4

A voltmeter

Question 5

True or False?

The voltmeter must be connected in parallel with the component

Answer 5

True

Question 6

Finish the sentence

The resistance in a wire increases as……..

Answer 6

The length of the wire increases

or

The thickness of the wire decreases

Question 7

When resistance is increased in a circuit what decreases as a result?

Answer 7

The current

Question 8

What is the equation for Ohm’s law?

Answer 8

V = I × R

Question 9

How do you calculate resistence?

Answer 9

R = V ÷ I

Question 10

3 A flows through a 240 V lamp. What is the resistance of the lamp?

Answer 10

Resistance = 240 ÷ 3 = 80 Ω

Question 11

What is the job of an ammeter?

Answer 11

To calculate the resistance of an electrical component, an ammeter is used to measure the current.

Question 12

What is the equation for calculating energy transfered?

Answer 12

E = V × Q

Question 13

How much energy is transferred when the potential difference is 120 V and the charge is 2 C?

Answer 13

Energy transferred = 120 × 2 = 240 J

Question 14

Which term describes the relationship between resistance and the cross section of a wire?

Answer 14

Inversely proportional