Waec Physics Past Questions For Year 1995
Question 16
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
Question 17
A ray of light is incident on mirror m1 and after reflection is incident on mirror m2 as shown in the diagram, calculate the angle of reflection of the ray at mirror m2
- A. 120o
- B. 90o
- C. 60o
- D. 45o
- E. 30o
Question 18
When two objects P and Q are supplied with the same quantity of heat, the temperature change in P is observed to be twice that in Q. lf the masses of P and Q are the same, calculate the ratio of the specific heat capacities of Q to P.
- A. 4 : 1
- B. 2 : 1
- C. 1 : 1
- D. 1 : 2
- E. 1 : 4.
Question 19
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
Question 20
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
