The following devices use plane mirrors in their operations, except
- A. periscope
- B. sextant
- C. kaleidoscope
- D. binoculars
The ability of a wave to spread around corners is called
- A. polarisation
- B. dispersion
- C. diffraction
- D. reflection
A certain wave has a speed of 20ms-1. If the frequency of the wave is 0.25Hz, calculate the distance between successive crests of the wave
- A. 5.0m
- B. 40.0m
- C. 50.0m
- D. 80.0m
Dew point is not affected by
- A. temperature
- B. wind
- C. the amount of water vapour in the atmosphere
- D. atmospheric pressure
A solid of mass 0.5kg initially at 50oC melts at 60oC. Calculate the quantity of heat required to melt it completely. [specific heat capacity of the solid =2.0KJ kg-1K-1][Specific latent heat of fusion of solid =1.0 KJ kg-1]
- A. 1500J
- B. 10000J
- C. 10500J
- D. 15000J
An electric drill rated 400W is used to drill a hole in copper of mass 400g in 20s. Calculate the rise in temperature if all the heat produced is absorbed by the copper. [specific heat capacity of copper = 400Jkg-1K-1]
- A. 100oC
- B. 75oC
- C. 50oC
- D. 45oC
Specific heat capacity 36.4 Jkg-1 K-1 of a body means that when 36.4J of heat energy is supplied to a body of
- A. mass 100kg the temperature rises by 1k
- B. mass 1kg, the temperature by 1000K
- C. mass 1kg, the temperature rises by 1K
- D. mass 100kg, the temperature rises by 1000k
The pressure P, volume V, and absolute temperature T of a given mass of an ideal gas change simultaneously. Which of the followng equations is correct about the gas?
- A. PV = \(\frac{constant}{T}\)
- B. \(\frac{P}{T} = Constant\)
- C. \(\frac{P}{V} = \frac{constant}{T}\)
- D. \(\frac{I}{T} = \frac{constant}{PV}\)
In a thermos flask, heat loss by radiation is minimizes by the
- A. silvered surfaces
- B. vacuum within the doubled walls
- C. plastic stopper
- D. cork support
The advantages of the thermoelectric thermometer include the following characteristics except that it
- A. can measure rapidly changing temperatures
- B. can measure high and low temperature
- C. can measure high and low temperature almost at a point
- D. is fairly sensitive
a thermometer records 680 mmHg at steam point and 440 mmHg at ice point. The temperature it records at 380 mmHg is
- A. -25oC
- B. -20oC
- C. 20oC
- D. 25oC
a machine is said to be a third class lever when the
- A. load is between the fulcrum and effort
- B. fulcrum is between the effort and the load
- C. effort is between the fulcrum and load
- D. fulcrum is directly below the load
Which of the following sources of energy is/are exhausible? i. Solar ii. Fossil fuels iii. Tidal power
- A. ii, and iii
- B. i and ii only
- C. i and iii only
- D. ii only
A moving body of mass 25.0kg undergoes a uniform retardation of 20.0ms-2. Calculate the magnitude of the retardating force
- A. 1.25N
- B. 8.00N
- C. 45.00N
- D. 500.00N
A vertical string, suspended from a fixed point and having a small mass attached to the free end is set into oscillations. Which of the following statements about the system are correct? i. The potential energy of the mass is a minimum at the middle of the swing ii. Its kinetic energy is a maximum at the middle of the swing iii. The sum of the potential and kinetic energies is constant throughout the swing
- A. i,ii and iii
- B. i and ii only
- C. ii and iii only
- D. i and iii only
simple harmonic oscillator has a period of 0.02s and amplitude of 0.25m. Calculate the speed in ms-1 at the centre of the oscillation
- A. 125\(\pi\)
- B. 25.00\(\pi\)
- C. 100.00 \(\pi\)
- D. 400.00\(\pi\)
Which of the following statements best describes a rigid body? A body which
- A. is not equally deformed
- B. when deformed regains it shape
- C. is brittle
- D. when deformed remains deformed
a body is projected horizonatlly from the top of a cliff 45m above the ground. if the body lands at a distance 30m from the foot of the cliff, calculate the speed of projection. [g = 10ms-2]
- A. 10ms-1
- B. 15ms-1
- C. 20ms-1
- D. 30ms-1
The average speed of an object is determined by dividing the sum of its initial and final speeds by two only when the acceleration is
- A. changing
- B. uniform
- C. increasing
- D. decreasing
Two cars X and Y travelling in opposite directions along the same high way at uniform velocities 110 kmh-1 and 90kmh-1 respectively pass each other at a certain point. The velocity of X relative to Y at the time they pass each other is
- A. 200 kmh-1
- B. 100 kmh-1
- C. 40 kmh-1
- D. 20 kmh-1
Which of the following statements about moving particle is correct?
- A. if the resultant force acting on the particle is zero, then it is in dynamic equillibrium
- B. If the resultant force acting on the acting on the particle is greater than zero, then it is moving with a uniform velocity
- C. the rate of change of its momentum with time tales place in a direction opposite to that of its motion
- D. the particle falling freely covers equal distances in equal time interval