21.A body accelerates uniformly from rest at 6ms⁻² for 8sec and then decelerates uniformly to rest in the next 5 seconds. The magnitude of the deceleration is
- A. 9.6ms⁻²
- B. 48ms⁻²
- C. 24.0ms⁻²
- D. 39.4ms⁻²
22.A coil of copper wire N turns in a kept rotating between the poles of a permanent magnet such that the magnetic flux linking the coil changes continuously. Which of the following statement is TRUE?
- A. an E.M.F is induced in the coil such that when the change of flux is positive the emf is positive, and when the change of flux is negative, the emf is negative
- B. An emf is induced in the coil whose magnitude is inversely proportional to both the number of turns in the coil and the rate of change of magnetic flux
- C. An emf is set in the permanent magnet which reduces the flux in the coil to zero
- D. A current flows in the coil and an emf is setup proportional to both the rate of change of the flux and the number of turns
23.The half-life of a radioactive element is 9 days. What fraction of atoms has decayed in 36 days
- A. 1/16
- B. 1/4
- C. 1/2
- D. 15/16
24.Two nearly equal masses are connected by a string passing over massless, frictionless pulley. This physical system is called Atwood machine. The two masses are 195g and 205g, determine the acceleration of the masses.
- A. 0.250.m/s²
- B. 0.025m/s²
- C. 0.35m/s²
- D. 0.35m/s²
25.A jar 20m deep is full of liquid of relative density 1.3. At what depth below the liquid surface is the pressure equal to the pressure exerted by a column of 5cm of mercury of relative density 13.6.
- A. 0.52m
- B. 6,670.80m
- C. 981m
- D. 0.05m.
26.An object moves along a circle from point P1 and point P2, if the distance travelled is one quarter of the circumference, determine the angular displacement.
- A. π/2 r
- B. π/4r
- C. π/8r
- D. π/3r
27.Which of the following are the two forces experienced by an object immersed in a fluid? I. weight II. Tension III. Buoyant force IV. Frictional force
- A. I
- B. II
- C. I and III
- D. III and IV
28.Which of the following are the characteristics of pressure in liquid? I. increases with depth II. Varies with depth III. The pressure acts equally IV. Pressure at all point at the same depth is the same
- A. I
- B. II
- C. III
- D. I, II, III and IV
29.The mass of a specific gravity bottle is 7.6g when it is empty. It is 12.4g when filled with kerosene and 13.6g when filled with distilled water. Calculate the relative density of kerosene.
- A. 1.25
- B. 1.0
- C. 0.90
- D. 0.80
30.A piece of solid substance weighs 80g in air, 60g when totally immersed in a liquid water and 66g in liquid X. Calculate the relative density of liquid X.
- A. 0.7
- B. 1.33
- C. 1.21
- D. 0.83
31.The triple point of water is a thermodynamic temperature at which of the following values
- A. 279.15K
- B. 100⁰C
- C. 37.5K
- D. 273.16K
32.A quantity of ice at -10⁰C is heated until the temperature of the heating vessel is 90⁰C. Which of the following constants is NOT required to determine the quantity of heat supplied to the vessel?
- A. specific latent heat of vaporization
- B. specific heat capacity of ice
- C. specific latent heat of fusion
- D. specific latent heat of water
33.The scent from a jar of perfume opened in one corner of a room is picked up in another part of the room. The perfume moves through the air molecules by
- A. Evaporation
- B. Osmosis
- C. Diffusion
- D. Convection
34.The ice and steam points of the thermometer are 20mm and 100mm respectively. A temperature of 75⁰C corresponds to Y mm on the thermometer. What is Y?
- A. 100mm
- B. 70mm
- C. 80mm
- D. 60mm
35.The most suitable type of mirror used for the construction of a searchlight is the
- A. Concave mirror
- B. Convex mirror
- C. spherical mirror
- D. parabolic mirror
36.An astronomical telescope is said to be in normal adjustment when the
- A. eye is accommodated
- B. focal length of objective lens is longer than that of an eye piece
- C. final image is at the near point of the eye
- D. final image is at infinity
37.Light waves and ripples of water are similar because both
- A. are longitudinal
- B. have the same velocity
- C. have the same frequency
- D. can be diffracted and refracted
38.A hydrogen tank of volume 0.08m³ at constant temperature is filled to a pressure of 30,000kpa. What was the original volume of the hydrogen when it was at a pressure of 2 atmosphere? (1 atm =100kpa)
- A. 12.00m³
- B. 120.00m³
- C. 24.00m³
- D. 2.40m³
39.An object of height 3.00cm is placed 10cm in front of a biconvex lens of a focal length 15cm. The image of the object is
- A. Real and 3.00cm tall
- B. Virtual and 3.00cm tall
- C. virtual and 9.00cm tall
- D. Real and 9.00cm tall
40.A 3000W electric cooker is to be used on a 200V mains circuit. Which of the fuses below can be used safely with the cooker?