The half life of a radioactive material is 12 days. Calculate the decay constant.

• A. 0.8663 day \(day^{-1}\)
• B. 0.04331 day \(day^{-1}\)
• C. 0.17325 day \(day^{-1}\)
• D. 0.05775 day \(day^{-1}\)

(a)(i) Define dew point. (ii) Explain why dew forms more quickly on the metal parts than on the rubber parts of a bicycle placed in the open overnight.

(b)(i) Explain the statement. the specific heat capacity of copper is 400 J/kg/K. (ii) Two metals, P and Q are supplied with the same quantity of heat.

If the ratio of the specific heat capacity of P to Q is 3 : 1 and their masses are in the ratio I:2 respectively.

calculate the ratio of the temperature rise of P to Q.

(c)(i) Define coefficient of thermal conductivity of a material.

(ii)

The diagram below illustrates a composite bar of iron and copper. The bar is insulated along its sides and it has a diameter of 10 mm. The length and thermal conductivity of the iron are 0.15 m and 40 W/m/K, respectively and those of copper are 0.05 m and 360 W/m/K, respectively. If the free ends of the iron and copper are kept at 100°C and 0°C respectively. calculate the (i) temperature at the interface between the bars; (ii) rate of heat flow along the bar.

Which of the following gives rise to the line spectra obtained from atoms?

• A. Kinetic energy of a moving atom
• B. Potential energy of an electron inside an atom
• C. Change of an electron from a higher to a lower energy level in the atom
• D. Disturbed proton in the nucleus

Resonance occurs when one vibrating object causes a second object to vibrate at its own natural

• A. amplitude
• B. speed
• C. frequency
• D. intensity

An object is released from rest at a height of 25m. Calculate the time it takes to fall to the ground. [g = 10ms^-2]

• A. 25.00s
• B. 10.00s
• C. 2.50s
• D. 2.24s

An electric kettle rated 1500W boils away 0.3kg of a liquid at its boiling point every 300s. Calculate the specific latent heat of the vaporisation of the liquid

• A. 1.5 x \(10^6Jkg^-1\)
• B. 1.35 x \(10^6Jkg^-1\)
• C. 1.5 x \(10^5Jkg^-1\)
• D. 4.5 x \(10^2Jkg^-1\)

A given mass of an ideal gas has a pressure of 500Nm^-2 at -13^oC. If its volume remains constant. Calculate its pressure at 247^oC.

• A. 25Nm^-2
• B. 50Nm^-2
• C. 500Nm^-2
• D. 1000Nm^-2

Which of the following is not a part of an A.C generator?

• A. Carbon brushes
• B. Slip rings
• C. Commutator
• D. Field magnet

For photoelectric emission, the threshold frequency is the

• A. maximum frequency of incident radiation that will eject electrons
• B. minimum fraquency of incident radiation required to eject electrons
• C. frequency which results in the emission of the greater number of electrons
• D. fraquency whch impacts greatest kinetic energy to emitte electrons

(a) Explain: (i) Fusion. (ii) Fission.

(b) State three advantages of fusion over fission in the generation of power

(c) Calculate in joules, the binding energy for

\(\frac{59}{27}\) Co

(Atomic mass of \(^{59}_{2} Co\) = 58.9332 u)

(Mass of proton = 1.00783u)

(Mass of neutron = 1.00867 u)

(Unified atomic mass unit, U = 931 MeV)

(1 eV = 1.6 x 10\(^{-19}\) J)