Total eclipse of the sun occurs when the
- A. earth is between the moon and the sun
- B. sun is between the moon and the earth
- C. moon is between the sun and the earth
- D. ozone layer is threatened
The pitch of an acoustic device can be increased by
- A. increasing the frequency
- B. increasing the amplitude
- C. decreasing the loudness
- D. decreasing the intensity
The difference between sound waves and light waves is that sound waves
- A. are transverse while light waves are longitudinal
- B. require a medium to travel while light waves does not
- C. can be diffracted but light waves cannot
- D. cannot be reflected but light waves can
The wavelength of signals from a radio transmitter is 1500mm and the frequency is 200kHz. What is the wavelength for a transmitter operating at 100kHz?
- A. 7500m
- B. 300m
- C. 75m
- D. 15m
Which of the following is the exclusive property of a transverse wave?
- A. diffraction
- B. refraction
- C. compression
- D. polarization
A well-lagged bar of length 100cm has its ends maintained at 100oC and 40oC respectively. What is the temperature at a point 60cm from the hotter end?
- A. 58oC
- B. 62oC
- C. 64oC
- D. 76oC
Which of the following statements give the TRUE difference between evaporation and boiling? i. Evaporation occurs at all temperatures while boiling occurs at a fixed temperature for a given pressure. ii. Evaporation is a surface phenomenon while boiling is an interior phenomenon. iii. Evaporation is affected by surface area while boiling is not.
- A. i and ii only
- B. i and iii only
- C. ii and iii only
- D. i, ii, iii.
A quantity of ice at 10oC is heated until the temperature of the heating vessel is 90oC. Which of the following constants is NOT required to determine the quantity of heat supplied to the vessel?
- A. specific heat capacity of ice
- B. specific heat capacity of water
- C. specific latent heat of fusion
- D. specific latent heat of vaporization
A temperature scale has a lower fixed point of 40mm and a upper fixed point of 200mm. What is the reading on this scale when a thermometer reads 60oC?
- A. 33.3mm
- B. 36.0mm
- C. 96.0mm
- D. 136.0mm
An electric kettle with negligible heat capacity is rated at 2000W. If 2.0kg of water is put in it, how long will it take the temperature of water to rise from 20OC to 100OC? [specific heat capacity of water = 4200Jkg-1k-1]
- A. 420S
- B. 336S
- C. 168S
- D. 48S
The equation PxVyTz = constant in charles’ law when
- A. x = 1, y = -1, z = 1
- B. x = 0, y = 1, z = -1
- C. x = 1, y = 0, z = -1
- D. x = 0, y = 1, z = 1
A piece of wood floats inside water at room temperature with a fraction of it above the liquid surface. As the temperature of the water is raised, the part of the wood above the liquid will
- A. decrease because the density of water decreases with temperature
- B. increase because the density of water decreases with temperature
- C. decreases because the density of water increases with water temperature
- D. increase because the density of water increases with temperature
A rectangular metal block of volume 10-6m3 at 273k is heated to 573k. If its coefficient of linear expansion is 1.2 x 10-5k-1, the percentage change of it volume is
- A. 1.5%
- B. 1.1%
- C. 0.4%
- D. 0.1%
Temperature is the measure of the
- A. quantity of heat transferred into the molecules of an object
- B. mean kinetic energy of the molecules of the object
- C. kinetic energy of any individual molecule of the substance
- D. amount of work done by the molecules of the object
The volume of an air bubble increases from the bottom to the top of a lake at constant temperature because
- A. atmospheric pressure acts on the surface of the lake
- B. pressure increases with depth
- C. density remains constant with pressure
- D. the bubble experiences an upthrust
A hydraulic press has a large circular piston of radius 0.8m and a circular plunger of radius 0.2m. A force of 500N is exerted by the plunger. Find the force exerted on the piston
- A. 8000N
- B. 4000N
- C. 2000N
- D. 31N
The energy contained in a wire when it extended by 0.02m by a force 500 N is
- A. 5J
- B. 10J
- C. 103J
- D. 104
Which of the following statements are TRUE about frictional force? i. it is always a disadvantage ii. it is sometimes a disadvantage iii. it always exist where there is a relative motion of two bodies that are in contact iv. it is sometimes very useful
- A. i, iii only
- B. i, iv only
- C. ii, iii only
- D. iii, iv only
A vehicle of mass m is driven by an engine of power P from rest. Find the minimum time it will take to acquire a speed
- A. \(\frac{mv^2}{2p}\)
- B. \(\frac{mv^2}{p}\)
- C. \(\frac{mv}{p}\)
- D. \(\frac{mv}{2p}\)
A uniform rod PQ of length 1m and mass 2kg is pivoted at the end p. If load of 14N is placed at the center of the rod, find the force that should be applied vertically upwards at Q to maintain the rod at equilibrium horizontally [g = 10ms-2]
- A. 68N
- B. 28N
- C. 17N
- D. 7N
A body is projected from the earth’s surface with the intention of letting it escape from the earth’s gravitational field. What is the minimum escape velocity of the body? [Earth’s radius = 6.4 x 103km, g = 10ms-2]
- A. 14 kms-1
- B. 13 kms-1
- C. 12 kms-1
- D. 11 kms-1