How much heat is required to convert 20 g of ice at 0oC to water at the same temperature? (Specific latent heat of ice = 336 J g-1)
- A. 1.35 x 103J
- B. 5.38 x 103J
- C. 6.72 x 103J
- D. 7.06 x 103J
- E. 8.06 x 103J
An iron rod of mass 2kg and at a temperature of 280oC is dropped into some quantity of water initially at a temperature of 30oC. lf the temperature of the mixture is 70oC, calculate the mass of the water. (Neglect heat losses to the surroundings). Specific heat capacity of iron = 460 J kgK) (Specific heat capacity of water = 4200 Jkg K)
- A. 0.58kg
- B. 0.77kg
- C. 1.15kg
- D. 1.50kg
- E. 2.04kg
The temperature of glass vessel containing 100cm3 of mercury is raised from 10oC to 100oC. Calculate the apparent cubic expansion of the mercury. (Real cubic expansivity of mercury = 1.82 x 10-4K-1) (Cubic expansivity of glass = 2.4 x 10-5K-1)
- A. 0.52cm3
- B. 1.42cm3
- C. 1.87cm3
- D. 5.22cm3
- E. 14.22cm3
The pressure of a given mass of gas changes from 200 Nm2 to 100 N m2, while its temperature drops from 127oC to – 73oC. Calculate the radio of the final volume of the gas to its initial volume.
- A. 2.4:1
- B. 2.0:1
- C. 1.2:1
- D. 1.0:1
- E. 1.0:2
An air bubble of volume 2 cm\(^3\) is formed 20m under water. What will be its volume when it rises to just below the surface of the water if the atmospheric pressure is equivalent to a height of 10m of water?
- A. 6cm3
- B. 4cm3
- C. 3cm3
- D. 2cm3
- E. 1cm3
Hot water at a temperature of t is added to twice that amount of water at a temperature of 30°C. If the resulting temperature of the mixture is 50°C. Calculate t.
- A. 90oC
- B. 80oC
- C. 50oC
- D. 40oC
- E. 30oC.
A body of specific heat capacity 450J kg-1 K-1 falls to the ground from rest through a vertical height of 20m. Assuming conservation of energy, calculate the change in temperature of the body on striking the ground level. (g = 10ms-2)
- A. 0oC
- B. 2/9oC
- C. 4/9oC
- D. 9/4oC
- E. 9/2oC
A brass rod is 2 m long at a certain temperature. Calculate the linear expansion of the rod for a temperature change of 100K. (Take the linear expansivity of brass as 1.8 x 10’5K”).
- A. 0.3600 m
- B. 0.1800 m
- C. 0.0360 m
- D. 0.0036m
- E. 0.0018 m
A mercury-in-glass thermometer reads – 20o at the ice point and 100o at the steam point. Calculate the celcius temperature corresponding to 70o on the thermometer.
- A. 41.0oC
- B. 50.0oC
- C. 62.5oC
- D. 70.0oC
- E. 75.0oC.
A body weighing 10 N in air is partially immersed in water. It displaces water of mass 0.3 kg. What is the upthrust on the body? (g = 10 ms-2)
- A. 13.0 N
- B. 7.0 N
- C. 3.3N
- D. 3.0N
- E. 0.3 N.
A machine has an efficiency of 60%. If the machine is required to overcome a load of 30 N with a force of 20 N calculate its mechanical advantage?
- A. 0.7
- B. 0.9
- C. 1.5
- D. 2.5
- E. 10.0
A car travelling at a uniform speed of 120km h-1 passes two stations in 4 minutes. Calculate the distance between the two stations.
- A. 8km
- B. 15km
- C. 22km
- D. 30km
- E. 60km
Which of the following will reduce the frequency of oscillation of a simple pendulum?
- A. Increasing the mass of the bob
- B. Decreasing the mass of the bob
- C. Increasing the length of the string
- D. Decreasing the length of the string
- E. Decreasing the amplitude of oscillation
At what angle to the horizontal must the nozzle of a machine gun be kept when firing to obtain a maximum horizontal range for the bullets?
- A. 0.0o
- B. 22.5o
- C. 30.0o
- D. 45. 0o
- E. 90.0o
The angular speed of an object describing a circle of radius 4m with a linear constant speed of 10 ms-1 is
- A. 40.00 rad s-1
- B. 14.00 rad s-1
- C. 2.50 rad s-1
- D. 1.58 rad s-1
- E. 0.40 rad s-1
A body of mass 7.5 kg is to be pulled up along a plane which is inclined at 30o to the horizontal. If the efficiency of the plane is 75%, what is the minimum force required to pull the body up the plane?
(g = 10ms-1)
- A. 5.0 N
- B. 20.0 N
- C. 50.0 N
- D. 75.0 N
- E. 200.0 N
A student found out from a simple pendulum experiment that 20 oscillations were completed in 38 seconds. What is the period of oscillation of the pendulum?
- A. 8.0s
- B. 3.8 s
- C. 2.0 s
- D. 1.9 s
- E. 0.5s
A boy cycles continuously through a distance of 1.0 km in 5 minutes. Calculate his average speed
- A. 0.3ms-1
- B. 3.3ms-1
- C. 16.6ms-1
- D. 20.0ms-1
- E. 200.0ms-1
Which of the following is a fundamental quantity?
- A. Heat capacity
- B. Electric current
- C. Torque
- D. Reactance
- E. Density