Physics Past Questions and Answers

A machine has a velocity ratio of 4. if it requires 800 N to overcome a load of 1600 N,what is the efficiency of the machine?

A 60%
B 50%
C 40%
D 2%

Question 7:

A reservoir 500 m deep is filled with a fluid of density 850 kgm^-3. If the atmospheric pressure is 1.05 x 10⁵ Nm^-2, the pressure at the bottom of the reservoir is.
[g = 10ms^-2]

A 4.72 x 10⁶ Nm^-2
B 4.36 x 10⁶ Nm^-2
C 4.28 x 10⁶ Nm^-2
D 4.25 x 10⁶ Nm^-2

Question 8:

A piece of iron weights 250 N in air and 200 N in a liquid of density 1000 kgm^-3. the volume of the iron is?

A 5.0 x 10^-2 ms^-2
B 4.5 x 10^--2 ms^-3
C 2.5 x 10^-2 ms^-8
D 2.0 x 10^-2 ms^-3

Question 9:

A clinical thermometer is different from other mercury in glass thermometers owing to

A The constriction on its stem
B The grade of mercury used in it
C Its long stem
D Its wide range of temperatures

Question 10:

I. Use a liquid with a high melting point.
II. use a liquid of high volume expansivity.
III. use a capillary tube of large diameter.
which of the above best describes how the sensitivity of a liquid-in-glass thermometer can be enhanced?

A I only
B II. only
C I and II only
D II and III only