When a number of identical small magnets are arranged in a line, the strength of the resultant magnet
- A. ia largest when they are arranged end to end
- B. is greatest when they are arrangedparallel with like poles adjacent to each other
- C. depends only on the number of magnets provided they arev parallel
- D. is greater when the magnets are arranged on a wooden surface than on a metaln surface
Two insulated charged spheres of different sizes and carrying opposite charges are connected together by a metallic conductor. Current will flow from one sphere to the other until both sphere
- A. carry the same magnitude and sign of charge
- B. are at the same potential
- C. are at the same temperature
- D. are of the same size
Which of the following pairs is NOT part of the electromagnetic spectrum? i. Radio waves. ii. Beta rays. iii. Gamma rays. iv. Alpha rays
- A. i and ii
- B. iii and iv
- C. i and ii
- D. ii and iv
Dispersion of light by a glass prism is due to the
- A. different colours of the glass
- B. different speeds of the various colours in glass
- C. defects in the glass
- D. high density of glass
When a yellow card is observed through a blue glass, the card would appear.
- A. black
- B. green
- C. red
- D. white
A far sighted person cannot see objects that are less than 100cm away. If this person wants to read a book at 25cm, what type and focal length of lens does he need?
- A. convex, 20cm
- B. concave, 20cm
- C. convex, 33cm
- D. concave, 33cm
The plane mirrors in a kaleidoscope are usually placed
- A. at an angle of 60o
- B. parallel to one another
- C. perpendicular to one another
- D. at an angle of 45o
The magnification of the image of an object placed in front of a convex mirror is \(\frac{1}{3}\). If the radius of curvature of the mirror is 24cm, what is the distance between its object and its image?
- A. 8cm
- B. 16cm
- C. 24cm
- D. 32cm
Light of wavelength 5000 x 10-8cm travels in free space with a velocity of 3 x 108ms-1. What is its wavelength in glass of refractive index 1.5?
- A. 3333 x 10-8cm
- B. 5000 x 10-8cm
- C. 6666 x10-8cm
- D. 750010-8cm
In a sound wave in air, the adjacent rarefactions and compressions are separated by a distance of 17cm. If the velocity of the sound wave is 340ms-1. Determine the frequency
- A. 10Hz
- B. 20Hz
- C. 1000Hz
- D. 5780Hz
When the tension in a sonometer wire is doubled, the ratio of the new frequency to the initial frequency is?
- A. \(\frac{1}{\sqrt2}\)
- B. \(\frac{1}{2}\)
- C. \(\sqrt2\)
- D. 2
A vibrator of frequency 60Hz is used in generating transverse stationary waves in a long thin wire, If the average distance between successive nodes on the wire is 45cm, find the speed of the transverse waves in the wire.
- A. 27ms-1
- B. 54ms-1
- C. 90ms-1
- D. 108ms-1
From the kinetic theory of gases, temperature is a
- A. form of energy and is proportional to the total kinetic energy of the molecules
- B. form of energy and is proportional to the average kinetic energy of the molecules
- C. physical property and is proportional to the total kinetic energy of the molecules
- D. physical property and is proportional to the average kinetic energy of the molecules
An electric heater is used to melt a block of ice of mass 1.5kg. If the heater is powered by a 12V battery and a current of 20A flows through the coil, calculate the time taken to melt the block of ice at 0oC. [specific latent heat of fusion of ice = 336 x 103Jkg-1]
- A. 76.0min
- B. 35.0min
- C. 21.0min
- D. 2.9min
A mass of gas at 7oC and 70cm of mercury has a volume of 1200cm3. Determine its volume at 27oC and pressure of 75cm of mercury.
- A. 1200cm3
- B. 1378cm3
- C. 4320cm3
- D. 4629cm3
A column of air 10.0cm long is trapped in a tube at 27oC. What is the length of the volume at 100oC?
- A. 12.4cm
- B. 13.7cm
- C. 18.5cm
- D. 37.0cm
The pressure on the gas of constant gas thermometer at the ice point is 325mm of mercury and at the steam point is 875mm of mercury. Find the temperature when the pressure of the gas is 190mm of mercury
- A. 30k
- B. 243k
- C. 300k
- D. 3003k
A piece of wood of mass 40g and uniform cross-sectional area of 2cm2 floats upright in water. The length of the wood immersed is
- A. 30cm
- B. 40cm
- C. 20cm
- D. 2cm
Which of the following devices are used to measure pressure? i. Aneroid barometer. ii. hydrometer. iii. hygrometer. iv. manometer.
- A. i and iii
- B. ii and iii
- C. iii and iv
- D. i and iv
A block-and-tackle system is used to lift a load of 20N through a vertical height of 10m. if the efficiency of the system is 40%, how much work is done against friction?
- A. 80J
- B. 120J
- C. 300J
- D. 500J
A thin film of liquid is trapped between two glass plates. The force required to pull the plates apart will increase if the
- A. surface tension of the liquid is reduced
- B. perpendicular distance between the plates is increased
- C. area of the liquid surface in contact with the plates is increased
- D. pressure of the air is decreased