(a) Explain the terms:

(i) transmutation as it relates to radioactivity; (ii) stopping potential.

(b) \(^{23}_{11}A + ^2_1B\) —> \(^p_qC\) + proton

\(^p_qC\) —> \(^r_sE\) + beta

A nucleus C, formed artificially from A and B radioactive and quickly decays to another nucli E as indicated in the nuclear equations abc Datermine the values of p, q, r and s.

(c) A certain metal of work function 1.6 eV is irradiated with ultra-violet light of wavelength 3.6 x 10\(^{-7}\) Calculate the maximum

(i) kinetic energy of ejected electron in joules;

(ii) speed of an emitted electron. (1eV = 1.6 x 10\(^{-18}\) J; C = 3.0 x 10\(^{8}\) ms\(^{-1}\); m, = 9.1 x 10\(^{-31}\) kg; h = 6.6 x 10\(^{-34}\) Js)

(d) If source of the ultra-violet light in (c) above is mo away from the surface of the metal, state the of on the maximum speed of the ejected electron

A metal is illuminated with a radiation of energy 6.88eV If the kinetic energy of the emitted electrons is 1.5OeV, calculate the work function of the metal.

• A. 0.22eV
• B. 4.59eV
• C. 5.38eV
• D. 8.38eV

Which of the following equations for the efficiency of a machine is correct?

• A. Efficiency = \(\frac{\text{Velocity Ratio}}{\text{Mechanical Advantage}}\) x 100%
• B. Efficiency = \(\frac{input}{output}\) x 100%
• C. Efficiency = \(\frac{\text{load distance}}{\text{effort distance}}\) x 100%
• D. Efficiency = \(\frac{\text{Mechanical Advantage}}{\text{Velocity Ratio}}\) x 100%

Define;

(i) Elasticity

(ii) Young's modulus

(iii) Force constant

In a tuned radio receiver R, L, C series circuit for resonance, the inductive and capacitive reactance XL and XC respectively are related as

• A. XL = XC
• B. XL = 1/2XC
• C. XL = 1/XC
• D. XL = 2XC

If a mango fruit dropped at a height of 50 meters. How long does it reach the ground? (take g = 10m/s2)

• A. 2 sec
• B. 3 sec
• C. 4sec
• D. 3.2sec

In a mass spectrometer, an ion of charge, q, and mass, m, moving in a path of radius, r, in a field of flux density, B, has a speed of

• A. \(\frac{qBr}{m}\)
• B. \(\frac{mr}{qB}\)
• C. \(\frac{qm}{Br}\)
• D. \(\frac{mq}{r}\)

a) What does the acronym LASER stand for?

b) What is a laser?

The quality of a note produced by a vibrating string is determined by the

• A. pitch of the note
• B. tension of the string
• C. material of the string
• D. presence of overtones

The photocell works on the principle of the

• A. voltaic cell
• B. emision of electrons by incident radiation
• C. emision of protons by incident electrons
• D. photographic plate