The phenomenon that makes sound persist when its source has been removed is known as
- A. acoustic vibration
- B. rarefaction
- C. echo
- D. reverberation
blowing air over a liquid aids evaporation by
- A. increasing its surface area
- B. decreasing its vapour pressure
- C. increasing its temperature
- D. decreasing its density
a ray of light which strikes a glass slab from air at normal incidence passes through the slab
- A. undeviated and undisplaced at a lower speed
- B. deviated and undisplaced at a lower speed
- C. deviated and displaced at a lower speed
- D. undeviated and displaced at a faster speed
water is a poor thermometric liquid because it
- A. is opaque
- B. is a poor conductor
- C. wets glass
- D. has low vapour pressure
A concave mirror of radius of curvature 40 cm forms a real image twice as large as the object.
the object distance is
- A. 10 cm
- B. 30 cm
- C. 40 cm
- D. 60 cm
If tension is maintained on a stretched string of length 0.6m, such that its fundamental frequency of 220Hz is excited, determine the velocity of the transverse wave in the string.
- A. 528 ms-1
- B. 264 ms-1
- C. 132 ms-1
- D. 66 ms-1
The time rate of loss of heat by a body is proportional to the
- A. difference in temprature between the body and its surroundings
- B. temperature of its surroundings
- C. ratio of the temperature of the body to that of its surroundings
- D. temperature of the body
Which of the following eye defects can be corrected using a cylindrical lens.
- A. myopia
- B. Astigmatism
- C. Presbyopia
- D. Chromatic abiration
the property that is propagated in a traveling wave is
- A. frequency
- B. amplitude
- C. energy
- D. wave lenght
To produce an enlarged and erect image with a concave mirror,the object must be positioned
- A. at the principal focus
- B. beyond the centre of curvature
- C. between the principal focus and the centre of the curvature
- D. between the principal focus and the pole
Which of the following is a characteristics of stationary waves?
- A. They are formed by two identical waves travelling in opposite directions
- B. they can be transverse or longitudinal
- C. The distance between two successive nodes is one wavelenght
- D. The antinode is a point of minimum displacement
I. Temperature.
II. Density of air molecules
III. Pressure
IV. Pitch
Which of the above will affect the velocity of sound in the air
- A. I and II only
- B. II and IV only
- C. I,II and IV only
- D. I,II,III nad IV
The radiator of a motor car is cooled by
- A. radiation
- B. conduction
- C. convection
- D. radiation and conduction
A coin place below a rectangular glass block of thickness 9cm and refractive index 1.5 is viewed vertically above the block. The apparent displacement of the coin is
- A. 3 cm
- B. 5 cm
- C. 6 cm
- D. 8 cm
The effect of a particle in a fluid attaining its terminal velocity is that the
- A. acceleration is maximum
- B. weight is equal to the retarding force
- C. buoyancy force is equal to the to the viscous retardind force
- D. buoyancy force is more than the weight of the fluid displaced
A particle in circular motion performs 30 oscillation in 6 seconds. Its angular velocity is
- A. 5 rad s-1
- B. 6 rad s-1
- C. 5π rad s-1
- D. 10π rad s-1
Two force each of 10N acts on a body, one towards the north and the other towards the east.
The magnitude and the direction of the resultant force are
- A. 20N, 45°E
- B. 20N, 45°W
- C. 10√2N, 45°W
- D. 10√2N, 45°E
If the distance between two suspended masses 10kg each is tripled, the gravitational force of attraction between them is reduced by
- A. one half
- B. one third
- C. one quarter
- D. one ninth
A body weighing 80N stands in an elevator that is about to move. The force exerted by floor on the body as the elevator moves upward with an acceleration of 5 ms-2 is
[g = 10ms-2]
- A. 40 N
- B. 80 N
- C. 120 N
- D. 160 N
The hydrostatic blood pressure difference between the head and the feet of a boy standing straight is 1.65 x 104 Nm-2. Find the height of the boy.
[ Density of blood = 1.1 x 103 kgm-3, g = 10ms-2]
- A. 0.5 m
- B. 0.6 m
- C. 1.5 m
- D. 2.0 m
A wheel and axle is used to raise a load of 500 N by the application of an effort of 250 N. If the radii of the wheel and the axle are 0.4 cm and 0.1 cm respectively, the efficiency of the machine is
- A. 20 %
- B. 40 %
- C. 50 %
- D. 60 %