A steel wire of length 0.50m is stretched between two fixed points and its fundamental frequency is 200Hz. The speed of the wave in the wire is
- A. 100ms-1
- B. 120ms-1
- C. 200ms-1
- D. 250ms-1
In a closed organ pipe producing a musical note, an antinode will always be produced at
- A. the closed end
- B. the open end
- C. the middle
- D. all the parts of the pipe
The physical properties of sound waves can best be described by
- A. reflection and diffraction
- B. polarization and reflection
- C. polarization and diffraction
- D. polarization and refraction
One valid assumption of the kinetic theory of gasses is the
- A. the molecules of a gas are constantly in a state of motion and the number of collision remains constant
- B. the number of molecule of gas increases with increasing pressure
- C. as the temperature increases, the number of collision made by the gas molecule remains constant
- D. the molecules of gas are all identical and are very small in size
A vapour is said to be saturated when
- A. more molecules return to the liquid than the amount that left it
- B. a dynamic equilibrium exists between the molecules of the liquid and the vapour molecules at a given temperature
- C. the vapour pressure is equal to the atmospheric pressure
- D. all molecules are moving with the same speed in all directions at a given temperature
How many grams of water at 17oC must be added to 42g of ice at 0oC to melt the ice completely? [specific latent heat of fusion of ice = 3.4 x 105Jkg-1, specific heat capacity of water = 4200Jkg-1k-1]
- A. 200g
- B. 300g
- C. 320g
- D. 400g
A 500W heater is used to heat 0.6kg of water from 25ºC to 100ºC in t\(_1\) seconds. If another 1000W heater is used to heat 0.2kg of water from 10ºC to 100ºC in t\(_2\), seconds, find \(\frac{t_1}{t_2}\)
- A. 50
- B. 5
- C. 5/4
- D. 1/5
A gas has a volume of 100cm3 at 27oC. If it is heated to temperature T until a final volume of 120cm3 is attained, calculate T
- A. 33oC
- B. 60oC
- C. 87oC
- D. 114oC
The linear expansivity of brass is 2 x 10-5C-1. If the volume of a piece of brass is 15.00cm3 at 00C, What is the volume at 100oC?
- A. 16.03cm3
- B. 16.00cm3
- C. 15.09cm3
- D. 15cm3
A platinum resistance thermometer records 3.0\(\Omega\) at 0oC and 8.0\(\Omega\) at 100oC. If it records 6.0\(\Omega\) in a certain environment, The temperature of the medium is
- A. 80oC
- B. 60oC
- C. 50oC
- D. 30oC
A solid of weight 0.600N is totally immersed in oil and water respectively. If the upthrust of oil is 0.210N and the relative density of oil is 0.875. Find the upthrust in water.
- A. 0.600N
- B. 0.360N
- C. 0.240N
- D. 0.180N
The atmospheric pressure due to water is 1.3 x 106Nm-2. What is the total pressure at the bottom of an ocean 10m deep? [Density of water = 1000kgm-3, g = 10ms-2]
- A. 1.3 x 107Nm-2
- B. 1.4 x 106Nm-2
- C. 1.4 x 105Nm-2
- D. 1.0 x 10 5Nm-2
Which of these statements are correct for the pressures in liquids? i. pressure in a liquid at a point acts equally in all directions. ii. pressure increases with depth. iii. pressure at a depth depends on the shape of the container. iv. pressure at the same depth in different liquids are proportional to the density at different liquids.
- A. i, ii, iii only
- B. i, ii, iv only
- C. i, iii, iv only
- D. ii, iii, iv only
The tendon in a man’s leg is 0.01m long. If a force of 5N stretches the tendon by 2.0 x 10-5m, calculate the strain on the muscle.
- A. 5 x 106
- B. 5 x 102
- C. 2 x 10-3
- D. 2 x 10-7
In a wheel and axle mechanism the diameters of the wheel and axle are 40cm and 8cm respectively. Given that the machine is 80% efficient, what effort is required to lift a load of 100N?
- A. 20N
- B. 25N
- C. 50N
- D. 80N
A parachute attains a terminal velocity when
- A. its density is equal to the density of air
- B. the viscous force of the air and the upthrust completely counteract its weight
- C. it expands as a result of reduced external pressure
- D. the viscous force of the air is equal to the sum of the weight and upthrust
A man whose mass is 80kg climbs a staircase in 20s and expends power of 120W. Find the height of the staircase.[g = 10ms-2]
- A. 1.8m
- B. 2.0m
- C. 2.5m
- D. 3.0m
A uniform meter rule weighing 0.5N is to be pivoted on a knife-edge at the 30cm-mark. where will a force of 2N be placed from the pivot to balance the meter rule?
- A. 95cm
- B. 25cm
- C. 20cm
- D. 5cm
The force of attraction between two point masses is 10-4N when the distance between them is 0.18m. If the distance is reduced to 0.06m, calculate the force.
- A. 1.1 x 10-5N
- B. 3.3 x 10-5N
- C. 3.0 x 10-4N
- D. 9.0 x 10-4N
A ball of mass 0.15kg is kicked against a rigid vertical wall with a horizontal velocity of 50ms-1. If it rebounced with a horizontal velocity of 30ms-1, Calculate the impulse of the ball on the ball · ·
- A. 3.0Ns
- B. 4.5Ns
- C. 7.5Ns
- D. 12.0Ns
In free fall, a body of mass 1kg drops from a height of 125m from rest in 5s. How long will it take another body of mass 2kg to fall from rest from the same height? [g = 10ms-1·]
- A. 5s
- B. 10s
- C. 12s
- D. 15s