p1- efficiency

Question 1

What is the formula for efficiency?

Answer 1

Efficiency = (Useful output energy / Total input energy) x 100%

Question 2

True or False: An efficiency of 100% means that all input energy is converted to useful output energy.

Answer 2

True

Question 3

Fill in the blank: Efficiency is expressed as a __________.

Answer 3

percentage

Question 4

What is the maximum possible efficiency of any machine?

Answer 4

100%

Question 5

Multiple Choice: Which of the following is a factor that can affect efficiency? A) Friction B) Temperature C) Material D) All of the above

Answer 5

D) All of the above

Question 6

What does it mean if a machine has low efficiency?

Answer 6

It means that a large portion of the input energy is wasted.

Question 7

True or False: Increasing friction in a machine will increase its efficiency.

Answer 7

False

Question 8

What type of energy is often lost in a non-efficient machine?

Answer 8

Heat energy

Question 9

Fill in the blank: The efficiency of a device can always be improved by __________ energy losses.

Answer 9

reducing

Question 10

Multiple Choice: If a light bulb uses 60 Joules of electrical energy and produces 30 Joules of light energy, what is its efficiency? A) 50% B) 60% C) 70% D) 80%

Answer 10

A) 50%