A solid material of volume 100\(cm^{-3}\) is heated through a temperature difference of 40°C. Calculate the increase in the volume of the material if its linear expansitivity is 2 x \(10^{-6}K{-1}\)

• A. 2.4 x\(10^{-2}cm^{-3}\)
• B. 1.6 x\(10^{-2}cm^{-3}\)
• C. 8 x\(10^{-2}cm^{-3}\)
• D. 5 x\(10^{-2}cm^{-3}\)

(a) Define ionization potential.

(b)(i) State the three types of emission spectra.

(ii) Name one source each which produces each of the spectra stated in (b)(i).

(c) In an x-ray tube, electrons are accelerated the target by a potential difference of 80 A Calculate the:

(i) speed of the electron;

ii) threshold wavelength of the electron. [h=6.6 x 10\(^{-34}\) Js; e = 1.6 x 10\(^{-19}\) C; Me = 9.1 x 10\(^{-31}\)

d) An x-ray photon of frequency 4.5 x 10\(^{-18}\) strikes an. electron, assumed to be at rest. If t electron absorbs all the photon energy, calculate the speed acquired by the electron. [ h = 6.6 x 10\(^{-34}\) Js; Me = 9.1 x 10\(^{-31}\) kg ]

A metallic sphere is heated from 27°C to 200°C Without change of state. Which of the following changes would have resulted from the heating?

• A. No changes occur in its volume and density
• B. Its volume increases and its density increases
• C. Its volume increases and its density decrease
• D. Its volume increases without a change in density

An object 4 cm high is placed 15 cm from a concave mirror of focal length 5 cm. The size of the image is

• A) 2 cm
• B) 3 cm
• C) 4 cm
• D) 5 cm

which of the following statements are TRUE of isotopes? i. isotopes of an element have the same chemical properties because they have the same number of electrons. ii. isotopes of elements are normally separated using physical properties. iii. isotopes of an element have the same number of protons in their nuclei.

• A. i and ii only
• B. i and iii only
• C. ii and iii only
• D. i, ii, and iii

Which of the following correctly explains why soft iron is proffered to steel in electromagnets? i. soft iron is more readily magnetized than steel. ii. soft iron is more readily demagnetized than steel. iii. soft iron retains magnetism more than steel.

• A. i only
• B. ii and iii only
• C. i and ii only
• D. i, ii, and iii.

The team rectilinear acceleration means the rate of increase of

• A. velocity along a circular path in a unit time
• B. distance along a rectangular path in a unit time
• C. displacement along a straight-line path in a unit time
• D. velocity along a straight-line path in a unit time

(a) (i) What is nuclear fission?

(ii) State the function of each of the following ma-terials in a nuclear fision reactor:

(\(\alpha\)) graphite, (\(\beta\)) boron rods; (\(\gamma\)) liquid sodium

(b) The table below gives some of the energy levels of a hydrogen atom.

(i) Draw the energy level diagram for the atom.

(ii) Determine the wavelength of the photon emitted when the atom goes from the energy state n = 3 to the ground state. [h = 6.6 x 10\(^{-34}\) Js, c = 3 x 10\(^{8}\)ms\(^{-1}\), e = 1.6 x 10\(^{-19}\)]

(c) A piece of ancient bone from an excavation site showed \(^{14}_{6}\)C activity of 9.5 disintegrations per minute per 1.0x10\(^{-3}\)kg. If a bone specimen from a living creature shows \(^{14}_{6}\)C activity of 12.0 disintegrations per minute per 1.0 x 1 0\(^{-3}\), determine the age of the ancient bone. [Half - life of \(^{14}_{6}\)C = 5572 years].

A body of mass 2kg is released from rest on a plane inclined at an angle of 60° to the horizontal. Calculate the acceleration of the body down the plane.[g = 10ms\(^{-2}\)]

• A. 3.1ms^-2
• B. 5.2ms^-2
• C. 6.0ms^-2
• D. 8.7ms^-2

Which part of the human eye performs the same function as the diaphragm in a lens camera?

• A. Choroid
• B. Retina
• C. Iris
• D. Cornea