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.
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.
The efficiency of energy conversion on the energy flow through a hydroelectric power is?
\(\frac{E1}{E2}\)
\(\frac{E3}{E2}\)
\(\frac{E2}{E1}\)+ E2
\(\frac{E2}{E3}\) + E1
Correct answer is B
Efficiency = \(\frac{\text{useful energy output from machine}}{\text{energy input into machine}}\)
= \(\frac{E3}{E2}\)
20.0kgms\(^{-1}\)
10.0kgms\(^{-1}\)
5.0kgms\(^{-1}\)
2.5kgms\(^{-1}\)
Correct answer is B
Impulse = Change in momentum
m (v - u)
5 (2.0)
= 5 x 2 = 10.0kgm\(^{-1}\)
= 10.0kgms\(^{-1}\)
Palm oil from a bottle flows out more easily after it has been heated because the
Molecules do not increase speed during the heating
Viscosity of oil is reduced
Oil molecules force each other out
Adhesion between the oil molecules and those of the bottle is increased
Correct answer is B
If a liquid is heated the particles are given more energy and move faster and faster expanding the liquid.The result is that liquids show a reduction in viscosity with increasing temperature. With high temperatures, viscosity increases in gases and decreases in liquids, the drag force will do the same.
Which of the following is the dimension of pressure
ML\(^{−1}\)T\(^{−2}\)
MLT\(^{−2}\)
ML\(^{2}\)T\(^{3}\)
ML\(^{−3}\)
Correct answer is A
Pressure = \(\frac{Force}{Area}\)
Pressure = m × \(\frac{a}{t}\)
= \(\frac{MLT^{−2}}{L × L}\)
= ML\(^{−1}\)T\(^{−2}\)
\(\frac{P}{v}\)
(\(\frac{1}{2}\))V
PV
\(\frac{P}{V^2}\)
Correct answer is A
P = F × \(\frac{S}{1}\)
P = F x V
F = \(\frac{P}{V}\)