L2 Scientific Principles MOCK

Which of the following pipes, each measuring 6m in length, will offer the greatest resistance to the flow of water?

• 15mm pipe with four elbows

• 15mm pipe with four machine bends

• 22mm pipe, which reduces down to 15mm halfway along its length

• d. 15mm pipe with two machine bends and two elbows.

What is the intensity of pressure acting at the base of a 7m long pipe, which has a head height of 3 meters (the cistern at the head of this pipe measures 500mm x 500mm x 500mm)?

• 19.81kPa

• 24.67kPa

• 29.43kPa

• 32.49kPa

Conduction occurs by:

• Heat travelling in a straight line through the air

• Heat travelling through or along a solid material

• Heat travelling via a chemical reaction

• Heat travelling via the motion of a fluid.

What is the freezing point of water at sea level?

• 100 0C

• 75 0C

• 25 0C

• 0 0C.

Which of the following materials is the best conductor of heat?

• Lead

• Low carbon steel

• Copper

• Cast iron.

With a downward pressure of 100kPa and a head of 10m, what would be the approximate pressure in bar?

• 100 bar

• 50 bar

• 10 bar

• 1 bar.

What would the fuse size be for a domestic appliance that has a power rating of 3kW?

• 13 amp

• 10 amp

• 5 amp

• 3 amp.

Which of the following values reflects the pH value for pure water?

• 1

• 4

• 7

• 11.

The limescale build-up in systems is caused by:

• Soft water

• Acidic water

• Temporary hard water

• Permanently hard water.

A change of state may occur when water is heated to:

• 25 0C

• 50 0C

• 75 0C

• 100 0C.