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Physics questions and answers

Physics Questions and Answers

If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.

126.

Which of these is a second-class lever?

A.

sugar tongs

B.

claw hammer

C.

plier

D.

wheelbarrow

Correct answer is D

Examples of first class levers are pliers, scissors, a crow bar, a claw hammer, a see-saw and a weighing balance.

A wheelbarrow, a bottle opener, and an oar are examples of second class levers

127.

Water is not a good thermometric liquid because it?

A.

expands unevenly between 0 ºC and 4 ºC

B.

maintains fixed density

C.

has low freezing point

D.

wets glass

Correct answer is D

Water is most anomalous at low temperatures, with a remarkable density maximum at 4°C.

water is not used as a thermometric liquid because it has low thermal expansivity, high specific capacity, high vapor pressure and wets glass.

128.

A reservoir is filled with liquid of density 2000 kgm1. Calculate the depth at which the pressure in the liquid will be equal to 9100 Nm2 (g = 10 ms2)

A.

0.262 m

B.

0.664 m

C.

0.819 m

D.

0.455 m

Correct answer is D

pressure = p, depth/height = h, density = d, gravity = g

p = hdg

pdg=h

9100102000=h

0.455m

129.

The potential energy in an elastic string of force constant k, which has an extension X is?

A.

kX

B.

KX2

C.

½KX2

D.

½K

Correct answer is C

elastic potential energy[Ee] = 12ke2.

130.

The vapour pressure?

A.

increases non-linearly with measuring temperature

B.

increases linearly with increasing temperature

C.

decreases linearly with increasing temperature

D.

decreases non-linearly ith measuring temperature

Correct answer is A

The vapor pressure of any substance increases non-linearly with temperature, often described by the Clausius–Clapeyron relation.

As the temperature of a liquid or solid increases its vapor pressure also increases.

Conversely, vapor pressure decreases as the temperature decreases. 

i.e. vapor pressure is directly proportional to temperature