A man hears his echo from a nearby hill 2s after he shouted. If the frequency of his voice is 260Hz and the wavelength is 1.29m, how far away is the hill?
- A. 330.0m
- B. 335.4m
- C. 660.0m
- D. 670.8m
Two tuning forks of frequency 256Hz and 260Hz are sounded close to each other. What is the frequency of the beats produced?
- A. 2Hz
- B. 4Hz
- C. 8Hz
- D. 258Hz
Which of the following correctly, describes the image of an object, 4cm from a diverging lens of focal length 12cm?
- A. The image is virtual, 3cm in front of the lens
- B. The image is real, 6cm behind the lens
- C. The image is virtual, 6cm in front of the lens
- D. The image is real, 3cm in front the lens
In a ray diagram for a thin converging lens, a ray that is not parallel to the optic axis but passes through the optic center will
- A. pass through undeviated
- B. pass through the center of curvature after refraction
- C. emerge parallel to the principal axis
- D. pass through the principal focus after refraction
A trough 12.0cm deep is filled with water of refractive index \(\frac{4}{3}\). By how much would a coin at the bottom of the trough appear to be displaced when viewed vertically from above the water surface?
- A. 3.0cm
- B. 6.0cm
- C. 9.0cm
- D. 16.0cm
When a plane mirror at which a ray is incident is rotated through an angle \( \theta \), the reflected ray will be rotated through
- A. \(\frac{1}{2}\)\(\theta\)
- B. \(\theta\)
- C. 2\(\theta\)
- D. 3\(\theta\)
The image in a pin-hole camera is
- A. errect and formed by refraction through a lens
- B. virtual and formed by dispersion
- C. erect and gets sharper as the hole becomes larger
- D. inverted and formed by the light from each point travelling in a straight line
Which of the following is TRUE of light and sound waves?
- A. they both transmit energy
- B. they both need a mediumfor propagation
- C. they are both transverse waves
- D. their velocities in air are equal
A boy timed 30 oscillations of a certain pendulum thrice and obtained 1min. 10s, 1min. 12s and 1min. 7s respectively.The mean period of oscillation of the pendulum is
- A. 0.14s
- B. 0.43s
- C. 2.32s
- D. 6.97s
A room is heated by means of a charcoal fire, An occupant of the room standing away from the fire is warmed mainly by
- A. convection
- B. radiation
- C. conduction
- D. reflection
The absolute temperature of a perfect gas is proportional to the average
- A. potential energy of the molecules
- B. seperation between the molecules
- C. kinetic energy of the molecules
- D. velocity of the molecules
The saturated vapour pressure of a liquid increases as the
- A. volume of the liquid increases
- B. volume of the liquid decreases
- C. temperature of the liquid increases
- D. temperature of the liquid decreases
How long does it take a 750W heater to raise the temperature of 1kg of water from 20oC to 50oC [specific heat capacity of water = 4200Jkg-1K-1]
- A. 84s
- B. 112s
- C. 168s
- D. 280s
What is the difference in the amount of heat given out by 4kg of steam and 4kg of water when both are cooled from 100oC to 80oC? [the specific latent heat of steam is 2,260,000Jkg-1, specific heat capacity of water is 4200Jkg-1K-1]
- A. 4200J
- B. 2,260,OOOJ
- C. 9,040,000J
- D. 9,380,000J
A brass rod is 2m long at a certain temperature. What is the length for a temperature rise of 100K, if the expansivity of brass is 18 x 10-6K-1?
- A. 2.0036m
- B. 2.0018cm
- C. 2.1800
- D. 2.0360m
A thermometer with an arbitrary scale S, of equal division registers -30oS at the ice point and +90oS at the steam point. Calculate the Celsius temperature corresponding to 60oS
- A. 25.0oC
- B. 50.0oC
- C. 66.7oC
- D. 75.0oC
In which of the following is surface tension important?
- A. the floating of a ship in water
- B. the floating of a dry needle in water
- C. the floating of a baloon in air
- D. the diffusion of sugar solution across a membrane
A pilot records the atmospheric pressure outside its plane as 63cm of Hg while a ground observer records a reading of 75cm of Hg for the atmospheric pressure on the ground. Assuming that the density of the atmosphere is constant, calculate the height of the plane above the ground. (Relative density of Hg = 13.0 and that of air = 0.00013)
- A. 1200m
- B. 6300m
- C. 7500m
- D. 13800m
The mass of a stone is 15.0g when completely immersed in water and 10.0g when completely immersed in a liquid of relative density 2.0. The mass of the stone in air is
- A. 5.0g
- B. 12.0g
- C. 20.0g
- D. 25.0g
The spiral spring of a spring balance is 25.0cm long when 5N hangs on it and 30cm long, when the weight is 10N. What is the length of the spring if the weight is 3N assuming Hooke’s law is obeyed?
- A. 15.0cm
- B. 17.0cm
- C. 20.0cm
- D. 23.0cm
A 20kg mass is to be pulled up a slope inclined at 30o to the horizontal. If the efficiency of the plane is 75%, the force required to pull the load up the plane is [g = 10ms-2]
- A. 13.3N
- B. 73.5N
- C. 133.3N
- D. 53.2N