Question 4756:

A simple machine overcomes a load of \(4000 N\) when a force of \(200 N\) is applied. If the velocity ration of the machine is 25 , calculate the efficiency of the machine?

A. \(1,25 \%\)
B. \(80 \%\)
C. \(125 \%\)
D. \(0.8 \%\)

Question 4757:

A long sighted person is to read a book held at a distance of \(20 cm\) from the eyes. Which of the following will the person require to read the book with ease?

A. Nothing
B. Concave lens
C. Convex lens
D. Concave mirro

Question 4758:

An object at the bottom of a pool of liquid \(10 m\) depth is seen by an observer as if it is at Bm depth. What is the refractive index of the liquid

A. \(0.25\)
B. \(0.20\)
C. \(1.25\)
D. \(0.8\)

Question 4759:

Which of the following has the highest surface tension?

A. Soapy wate
B. Cold wate
C. Warm wate
D. Salt wate

Question 4760:

The emf developed in a circuit is directly proportional to the rate of change of magnetic flux. The above was a finding from ____________

A. Maxwell
B. Faraday
C. Ampere
D. Lenz