If the distance from a point source of sound is doubled, by what factor does the intensity decrease?
- A. 4.00
- B. 2.00
- C. 0.50
- D. 0.25
At what position will an object be placed in front of a concave mirror in order to obtain an image at infinity?
- A. At the pole of the mirror
- B. At the principal focus
- C. at the center of the curvature
- D. Between the principal focus and the center of curvature
The phenomenon where by the water droplets in the atmosphere combines with dust particles in the air to reduce visibility is
- A. cloud
- B. mist
- C. hail
- D. fog
If an object is placed between two parallel plane mirrors with their reflecting surfaces facing each other, how many images of the object will be formed?
- A. Infinite
- B. Eight
- C. Four
- D. Two
On a fairly cool rainy day when the temperature is 20oC, the length of a steel railroad track is 20m. What will be its length on a hot a dry day when the temperature is 40oC?
[coefficient of linear expansion of steel = 11 x 10-6K-1]
- A. 20.013m
- B. 20.009m
- C. 20.004m
- D. 20.002m
An open pipe closed at one end produces its first fundamental note. If the velocity of sound in air is P and t the length of the pipe, the frequency of the note is
- A. 2v/t
- B. v/5t
- C. v/4t
- D. v/2t
Thermal equilibrium between two object exist when
- A. the temperature of both objects are equal
- B. the quantity of heat of both objects is the same
- C. the heat capacities of both objects are the same
- D. one object losses heat continuously to the other
By what factor will the size of an object placed 10cm from a convex lens be increased if the image is seen on a screen placed 25cm from the lens?
- A. 15.0
- B. 2.5
- C. 1.5
- D. 0.4
A turning fork of frequency 340Hz is vibrated just above a cylindrical tube of height 1.2m. If water is slowly poured into the tube, at what maximum height will resonance occur.
[speed of sound in air = 340ms-1]
- A. 0.95m
- B. 0.60m
- C. 0.50m
- D. 0.45m
| TºC | 0 | 5 | 10 | 15 | 20 | 40 | 60 |
| S.V.P(mmHg) | 4.58 | 6.51 | 8.94 | 12.67 | 17.50 | 55.10 | 149.00 |
The table above shows the saturation vapour pressure against temperature in a certain town. If the vapour pressure in this town at 20oC is 10mmHg, what is the relative humidity?
- A. 170.0%
- B. 57.0%
- C. 17.5%
- D. 10.0%
A satellite is in a parking orbit if its period is
- A. less than the period of the earth
- B. more than the period of the earth
- C. equal to the period of the earth
- D. the square of the period of the earth
A 90cm uniform lever has a load of 30N suspended at 15cm from one of its ends. If the fulcrum is at the center of gravity, the force that must be applied at its other end to keep it in horizontal equilibrium is
- A. 15N
- B. 20N
- C. 30N
- D. 60N
A piece of stone attached to one end of a string is whirled round in a horizontal circle and the string suddenly cuts. The stone will fly off in a direction
- A. perpendicular to the circular path
- B. parallel to the circular path
- C. tangential to the circular path
- D. towards the center of the circle
The stylus of a phonograph record exerts a force of 7.7 x 10-2N on a groove of radius 10-5m. Compute the pressure exerted by the stylus on the groove
- A. 2.45 x 108 Nm-2
- B. 3.45 x 108 Nm-2
- C. 4.90 x 108 Nm-2
- D. 2.42 x 108 Nm-2
Water does not drop through an open umbrella of silk materials unless the inside of the umbrella is touched. This is due to
- A. capilarity
- B. osmotic pressure
- C. viscosity
- D. surface tension
If an object just begins to slide on a surface inclined at 30o to the horizontal,the coefficient of friction is
- A. √3
- B. √3/2
- C. 1/√2
- D. 1/√3
A hose of cross-sectional area 0.5m2 is used to discharge water from a water tanker at a velocity of 60ms-1 in 20s into a container. If the container is filled completely, the volume of the container is
- A. 240m3
- B. 600m 3
- C. 2400m 3
- D. 6000m3
The length of piece of glass block was measured by means of a vernier calliper as shown above. The length of the glass block is
- A. 1.63 cm
- B. 1.64 cm
- C. 1.65 cm
- D. 1. 66 cm
A test tube of radius 1.0cm is loaded to 8.8g. If is placed upright in water, find the depth to which it would sink
- A. 2.8cm
- B. 5.2cm
- C. 25.5cm
- D. 28.0cm
On top of a spiral spring of the force constant 500Nm-1 is placed a mass of 5 x 10-3 kg. If the spring is compressed downwards by a length of 0.02m and then released, calculate the height to which the mass is projected
- A. 8 m
- B. 4 m
- C. 2 m
- D. 1 m
A bead travelling on a straight line wire is brought to rest at 0.2 by friction. If the mass of the bead is 0.01kg and the coefficient of friction between the bead and the wire is 0.1, determine the work done by the friction
[g = 10ms\(^2\)]
- A. 2 x 10\(^{-4}\)
- B. 2 x 10\(^{-3}\)
- C. 2 x 10\(^{-1}\)
- D. 2 x 10\(^2\)