Physics Past Questions And Answers
The total area under a force-velocity graph represents
- A. energy
- B. momentum
- C. power
- D. pressure
How much heat is absorbed when a block of copper of mass 0.05kg and specific heat capacity 390Jkg-1K-1 is heated from 20oC to 70oC?
- A. 39 . 98 x 10-1J
- B. 9.75 x 102J
- C. 3.98 x 103J
- D. 9.75 x 103J
Ice of mass 50g at 0°C was completely melted by 70% of the total heat energy supplied. Calculate the total heat energy supplied [Specific latent heat of fusion of ice = 336\(Jg^{-1}\)]
- A. 2400J
- B. 6800J
- C. 7251J
- D. 24000J
The blade of a hoe feel colder to touch in the morning than the wooden handle because the
- A) handle is a better conductor of heat than blade
- B) handle contains stored energy in form of heat
- C) blade is a better conductor of heat than the handle
- D) blade is placed at a lower temperature than the heat
The diagram below illustrates the energy transitions of five electrons of an atom. Which of the transitions will produce the emission of longest wavelength?
- A. I
- B. II
- C. III
- D. IV
The function of the system of granulated carbon mixed with manganese (IV) oxide in a Letanche cell is to
- A. increase the e.m.f. of the cell to 2.0V
- B. prevent local action in the cell
- C. prevent polarisation in the cell
- D. make the cell black and hence a good radiator
Two cars X and Y travelling in opposite directions along the same high way at uniform velocities 110 kmh-1 and 90kmh-1 respectively pass each other at a certain point. The velocity of X relative to Y at the time they pass each other is
- A. 200 kmh-1
- B. 100 kmh-1
- C. 40 kmh-1
- D. 20 kmh-1
An object of height 2.5cm is places 20cm from a convex mirror of focal length 10cm. Calculate the height of its image.
- A. 2.5 cm
- B. 3.0cm
- C. 5.0cm
- D. 25.0cm
Which of the following instruments can be used to measure current in an a.c circuit?
- A. Hot wire ammeter
- B. Moving coil ammeter
- C. Tangent galvanometer
- D. Moving coil galvanometer
If a room is saturated with water vapour, the temperature of the room must be
- A. at 0oC
- B. above the dew point
- C. at 100oC
- D. below or at the dew point