9189PH2SCIENCEPPT6

According to Ohm's law, if you have any two electrical values, what can you always find?

• A third value using the Ohm's law triangle

• The power using the power triangle

• The resistance using the power triangle

• The voltage using the Ohm's law triangle

What does the Ohm's law triangle help to define?

• The relationships between (V) voltage, (I) current and (R) resistance

• The relationships between (P) power, (V) voltage, and (I) current

• The relationships between (P) power, (V) voltage, (I) current and (C) capacitance

• The relationships between (C) capacitance, (R) resistance, and (L) inductance

What is represented at the top of the Ohm's law triangle?

• I (Current)

• R (Resistance)

• V (Voltage)

• P (Power)

Why is an understanding of Ohm's law relevant to a plumber?

• To calculate water pressure

• To determine appropriate fuse sizes

• To install plumbing fixtures

• To measure the length of pipes

What must a plumber check when a customer requests the installation of a new shower?

• The color of the shower tiles

• The brand of the shower

• Whether the existing circuit and circuit protective device (MCB) can handle the power

• The type of shower head

What size fuse or circuit protection device is required for the immersion heater?

• 10A MCB

• 16A MCB

• 20A MCB

• 25A MCB

If an immersion heater has a power of 3.5kW and the voltage is 230V, what is the calculated current?

• 10.2 Amps

• 12.2 Amps

• 15.2 Amps

• 17.2 Amps

What is the current flowing to an 8kW shower fed from a 230V supply according to Ohm's law?

• A) 34.7 Amps

• B) 24.7 Amps

• C) 44.7 Amps

• D) 54.7 Amps

What is the resistance of the motor windings if a pump motor with a run current of 0.23A is supplied with 230V?

• 500Ω

• 1,000Ω

• 230Ω

• 0.23Ω

How do you calculate the resistance (R) using Ohm's law if the current (I) and voltage (V) are known?

• R = I / V

• R = V + I

• R = V - I

• R = V / I