Waec Physics Past Questions For Year 1990
Question 56
When the pressure of the gas in a discharge tube is gradually lowered. I. there is a violet glow in the tube II. the glow in the tube splits into bands which get further apart. III, the glow and the bands eventually disappear and there is a green fluorescence in the tube. IV. the tube breaks into pieces. Which of the following are correct?
- A. I and II only
- B. I and III only
- C. I and IV only
- D. I, II and III only
- E. I, II III and IV
Question 57
Which of the following is not an evidence of the particle nature of matter?
- A. Diffusion
- B. Brownian motion
- C. Diffraction
- D. Crystal structure
- E. Photoelectricity
Question 58
What is the difference between a crystalline and an amorphous solid? A crystalline solid
- A. has cubic structure while amorphous solid has hexagonal structure
- B. has regularly-repeating pattern while an amorphous solid has not
- C. is white while amorphous solid is yellow
- D. is always hard while amorphous solid is always soft
- E. melts on heating while an amorphous solid sublimates on heating.
Question 59
Which of the following is not crystal?
- A. Sodium chloride
- B. Lead
- C. Copper (II) tetraoxosulphate (VI)
- D. Glass
- E. Germanium
Question 60
Viscosity in a liquid does not depend on the
- A. nature of the liquid
- B. relative velocity between the liquid layers
- C. area of the surfaces in contact
- D. temperature of the liquid
- E. normal reaction between the liquid layers
