Physics Past Questions and Answers

The density 400cm³ of palm oil was 0.9gcm^-3 before frying. If the density of the oil was 0.6gm^-3 after frying,assuming no loss of oil due to spilling, its new volume was

A 360cm³
B 600cm³
C 240cm³
D 800cm³
E 450cm³

Question 2:

The density 400cm³ of palm oil was 0.9gcm^-3 before frying. If the density of the oil was 0.6gm^-3 after frying,assuming no loss of oil due to spilling, its new volume was

A 360cm³
B 600cm³
C 240cm³
D 800cm³
E 450cm³

Question 3:

Which of the following statements defines correctly the efficiency of a machine?

A The load carried by the machine divided by effort required in carrying the load
B The distance moved by the load divided by the distance moved by the effort
C The useful work done by the machine divided by the total work put into the machine
D The movement of the load divided by the movement of the effort about the same point
E The temperature at the end of the application of the machine divided by the initial temperature

Question 4:

A 500kg car which was initially at rest travelled with an acceleration of 5m sec^-2, its kinetic energy after 4 seconds was

A 10⁵J
B 2.5 x 10³J
C 2 x 10³J
D 5 x 10³J
E 5 x 10^5J`

Question 5:

Two closed vessels contain equal volumes of boiling water and are identical except that one is blackened on the outside while the other is polished. Which of the following is correct?

A The polished vessel will cool faster because a polished surface is a good radiator
B The polished vessel will cool faster because it will absorbe less heat from the room
C The black vessel will cool faster because it is a better conductor of heat
D The polished vesselwill cool faster because it reflects heat better
E The black vessel will cool faster because a black surface radiates heat faster than a polished one