Which of the following have the longest wavelengths?

• A. Infra-red rays
• B. Gamma rays
• C. X-rays
• D. Radio waves

How many times do the hands of a clock overlap in 24 hours?

• A. 22
• B. 24
• C. 20
• D. 48

The craft industry associated with the late Ladi Kwali in Nigeria is?

• A. weaving
• B. pottery
• C. carving
• D. dyeing

(a)(i) State Einstein's equation of photoelectric effect

(ii) What conservation principle does the equation represent?

(b) List three applications of photocells

(c) A photo emissive surface has a threshold frequency of 4.02 x 10\(^{14}\)Hz. If the surface is illuminated by light of frequency 5.0 x 10\(^{15}\)Hz, calculate the:

(i) threshold wavelength;

(ii) work function;

(iii) kinetic energy of the emitted photoelectrons. [ c = 3.0 x 10\(^{8}\) ms\(^{-1}\), h = 6.63 x 10\(^{-34}\) Js]

Ash and cinder cones are associated with

• A. Ozone depletion
• B. Hurricanes activities
• C. Earthquakes
• D. Volcanic eruption

CuSO₄ 5H₂O can be obtained from an aqueous solution of copper (ll) tetraoxosulphate (VI) by

• A. evaporation to dryness
• B. using chromatography
• C. precipitation
• D. crystallization

Vapour is said to be saturated on top of an enclosed liquid if _________

• A. The rate of condensation is greater than that of vapourization
• B. The rate of condensation is equal to that of vapourization
• C. There is neither condensation nor vaporization of the liquid
• D. The rate of condensation is less that that of vaporization

When an industry or company is nationalized, the state becomes

• A. the major shareholder
• B. the mini shareholder
• C. the only shareholder
• D. an equal shareholder with other individuals

The very bright colours in some types of mushroom

• A. are warning that they may be poisonous
• B. indicate they are very taste
• C. attract potential transporters of the spores
• D. perform the same function as bright colours in flowers

The derived unit of pressure can be expressed as

• A. kgms^-2
• B. kg m^-1s^-2
• C. kg m^-2s^-2
• D. kg m^-1s²