Satellite communication network makes use of?
- A. visible light
- B. sound wave
- C. radio wave
- D. infra-red wave
When very hot water is poured into two identical thin and thick glass tumblers in equal volumes, the thick one cracks because?
- A. of the even expansion of glass
- B. glass is a crystal
- C. glass is a good conductor of heat
- D. of the uneven expansion of gass
I. Melting
II. Boiling
III. Refraction
IV. Conduction
Which combination of the above is evident of the molecular nature of matter?
- A. II , III and IV only
- B. I ,II and IV only
- C. I , III and IV only
- D. I , II and III only
The process whereby a liquid turns spontaneously into vapour is called?
- A. regelation
- B. sublimation
- C. boiling
- D. evaporation
I. reproducibility
II. Sensibility
III. High terminal capacity
iv. High accuracy
The quantities of a good thermometer include?
- A. I, II and IV only
- B. I, III and IV only
- C. I, II and III only
- D. II, III and IV only
The process whereby the molecules of different substances move randomly is called?
- A. capillarity
- B. surface tension
- C. osmosis
- D. diffusion
A body of mass 36kg falls through a viscous liquid which offers a drag force of 260N on the body. The upthrust on the body at terminal velocity is?
[g = 10ms2]
- A. 100N
- B. 620N
- C. 50N
- D. 310N
A 3m3 volume of liquid W of density 200kgm3 is mixed with another liquid L of volume 7m3 and density 150kgm-3. the density of mixture is?
- A. 165kgm-3
- B. 100kgm-3
- C. 265kgm-3
- D. 350kgm-3
When the temperature difference between the wet and dry bulbs of a hygrometer is high, this indicates that
- A. it is about to rain
- B. the relative humidity is high
- C. there is plenty of sunshine
- D. the relative humidity is low
which of the following materials is a conductor?
- A. Glass
- B. Wax
- C. Sodium
- D. Plastic
The current in a reverse-biased junction is due to?
- A. minority carriers
- B. electrons
- C. majority carriers
- D. holes
A transformer is rated 240v. If the primary coil is 4000 turns and the secondary voltage 12v, determine the number of turns in the secondary coil.
- A. 200
- B. 100
- C. 250
- D. 150
the ray which causes gas molecules to glow is known as
- A. cathode ray
- B. anode ray
- C. molecular ray
- D. gamma ray
the ray which causes gas molecules to glow is known as
- A. cathode ray
- B. anode ray
- C. molecular ray
- D. gamma ray
The charge carriers in gasses are
- A. ions only
- B. electrons and ions
- C. electrons and holes
- D. electrons only
A silicon material is dopped with an element of a certain group and an n-type semi-conductor is formed. the most likely group of the element is
- A. V
- B. III
- C. I
- D. II
When impurities are added to semi-conductors, the conductivity of the semi-conductor
- A. increases then decreases
- B. increases
- C. decreases
- D. remains constant
a proton moving with a speed of 1.0 x 106ms-1 through a magnetic field of 1.0T experiences a magnetic force of magnitude 8.0 x 10-14 N. The angle between the proton”s velocity and the field is
- A. 60°
- B. 90°
- C. 30°
- D. 45°
the time it will take a certain radioactive material with a half-life of 50 days to reduce to 1/32of its original number is
- A. 250days
- B. 150days
- C. 300days
- D. 200days
In an a.c circuit that contains only a capacitor, the voltage lags behind the current by
- A. 180°
- B. 90°
- C. 60°
- D. 30°
An object is projected for the hieght of 80 m above the ground with a velocity of 40ms-1 at the angle of 30° to the horizontal. The time of flight
- A. 8 s
- B. 4 s
- C. 16 s
- D. 10 s