Transformer and Electricity Quiz

What does a step-up transformer do?

• Decreases the current of a power source

• Increases the current of a power source

• Decreases the potential difference of a power source

• Increases the potential difference of a power source

What is the formula for calculating electrical power?

• P = V × I

• P = V / I

• P = I / V

• P = V + I

In a 100% efficient transformer, what is true about input and output power?

• Input power equals output power

• Input power is greater than output power

• Input power is less than output power

• Input power is unrelated to output power

What is the unit of potential difference?

• Volts

• Amps

• Watts

• Ohms

What is the primary function of a transformer?

• To change the potential difference of a power source

• To store electrical energy

• To convert AC to DC

• To generate electricity

What is the relationship between the number of turns on the coils and the potential difference in a transformer?

• The ratio of the potential differences is equal to the ratio of the number of turns

• The potential difference is directly proportional to the number of turns

• The potential difference is inversely proportional to the number of turns

• There is no relationship

What is the potential difference across the secondary coil if a transformer has 20 turns on the primary coil, 800 turns on the secondary coil, and an input potential difference of 500 V?

• 2,000 V

• 20,000 V

• 200 V

• 50 V

What is the current drawn from the mains supply if a transformer steps up 115 V to 230 V and a current of 5 A flows through the secondary coil?

• 1 A

• 10 A

• 2.5 A

• 5 A

What is the symbol for potential difference across the primary coil?

• Vp

• Vs

• Ip

• Is

What is the symbol for the number of turns on the secondary coil?

• Ns

• Np

• Vs

• Vp