Unit 8 Science principles 2 OC 1-6

What is the efficiency of shower that has an input power of 8kW and an output of 6.75kW

• 82%

• 88%

• 84%

• 118%

What is the SI unit of density?

• kgm3

• kgm2

• kg/m

• kg/m3

What is the total power in a 100 volt DC circuit that contains two 100Ω resistors connected in series?

• 25Watts

• 50Watts

• 100Watts

• 0.5Watts

In an atom, what is the name given to a particle with a negative charge?

• Proton

• Electron

• Neutron

• Necleus

In an atom, what is the name given to a particle with no charge?

• Proton

• Electron

• Neutron

• Nucleus

In an atom, what is the name given to a particle with a positive charge?

• Proton

• Electron

• Neutron

• Nucleus

What can improve voltage drop in a circuit?

• lower the csa of the cables

• longer cable run in the circuit

• increase the csa of the cables

• increase the supply voltage by 100%

Electrical Energy is transmitted around the UK and Ireland using?

• Local Distribution Networks

• Private Networks

• The National Grid

• The International Grid

Transformers are used in the National Grid system to?

• Boost the power transmitted

• Minimise power loss in the network

• Ensure 100% efficiency

• Make the received power more than the generated power

A circuit consists of two resistors (5Ω & 20Ω) connected in parallel. Another resistor (10Ω) is connected in series to the parallel combination. Calculate the overall resistance?

• 20 Ω

• 35 Ω

• 13Ω

• 14 Ω