Curriculum
Course: Igcse Physics
time left:
:
:
Login

Curriculum

Igcse Physics

1. Motion, Forces and Energy

0/161 Dr Dabour Hub Science Diagram and Course Material

2. Thermal Physics

0/75 Dr Dabour Hub Science Diagram and Course Material

3. Waves

0/77 Dr Dabour Hub Science Diagram and Course Material

4. Electricity and Magnetism

0/119 Dr Dabour Hub Science Diagram and Course Material

5. Nuclear Physics

0/39 Dr Dabour Hub Science Diagram and Course Material

6. Space Physics

0/47 Dr Dabour Hub Science Diagram and Course Material
Quiz

1.7.7 Efficiency – Check yourself

Submit quiz
Once you submit, you will no longer be able to change your answers. Are you sure you want to submit the quiz?
Cancel Submit
  • Questions count: 6
  • Passing grade: B+
  • Time limit: 10 minutes
Start Quiz
1.
Efficiency is calculated as
input ÷ output × 100%
useful ÷ wasted
output ÷ input × 100%
wasted × 100%
2.
A machine uses 200 J and gives 150 J of useful work. Efficiency is
25%
75%
50%
133%
3.
Which efficiency is impossible?
35%
105%
100%
5%
4.
A device wastes 30 J out of an input of 120 J. Its efficiency is
25%
90%
30%
75%
5.
Which will not improve the efficiency of a bicycle?
Adding rough surfaces to the axle
Oiling the chain
Pumping the tyres
Streamlined clothing
6.
A filament lamp is only about 5% efficient. The rest of the input is mainly
sound
light
thermal energy
chemical energy
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
Part of 1. Motion, Forces and Energy — see every lesson and quiz in this unit.
Accepted payment methods