Waec Physics Past Questions For Year 1992
Question 16
A metal of mass 1.5 kg was heated from 27oC to 47oC in 4 minutes by a boiling ring of 75 W rating. Calculate the specific heat capacity of the metal, (Neglect heat losses to the surrounding)
- A. 2.5 X103J kg-10C-1
- B. 6.0 X102J kg-10C-1
- C. 2.5 x 102J kg-10C-1
- D. 1.4 X102J kg-10C-1
- E. 1.0 x 102J kg-10C-1
Question 17
Which of the following instruments is used to measure relative humidity?
- A. Hydrometer
- B. Barometer
- C. Manometer
- D. Hypsometer
- E. Hygrometer
Question 18
A small circular membrane is 10cm below the surface of a pool of mercury when the barometric height is 76 cm of mercury. If the density of mercury is 13600\(kgm^{-3}\), what is the pressure on the membrane in \(Nm^{-2}\)? \((g =10ms^{-2})\)
- A. 1.17 x 107 Nm-2
- B. 6.80 x 105Nm-2
- C. 1.17x105Nm-2
- D. 1.03 x 105Nm-2
- E. 1.36 x104 Nm-2
Question 19
Which of the following best explains why a person suffers a more severe burn when his skin is exposed to steam than when boiling water pours on his skin?
- A. Steam is at a higher temperature than boiling water
- B. Steam possesses greater heat energy per unit mass than boiling water
- C. Steam spreads more easily over a wider area of the skin man boiling water
- D. Steam penetrates more deeply into the skin than boiling water
- E. the specific latent heat of vaporization is released in changing from boiling water to steam
Question 20
A gas which obeys Charles’ law exactly has a volume of 283cm3 at 10oC. What is its volume at 30oC?
- A. 142cm3
- B. 293cm3
- C. 303cm3
- D. 566cm3
- E. 849cm3
