(a) Explain the following terms:
(i) viscosity;
(ii) terminal velocity.
(b)(i) Describe an experiment to determine the terminal velocity of a steel ball falling through a jar of glycerine..
(ii) State two precautions that should be taken to ensure accurate result.
(c) State two
(i) effects of viscosity
(ii) applications of viscosity.
(a) What is meant by the statement: The linear expansivity of a solid is \(1.0 \times 10^{-5}K^{-1}\)?
(b)(i) Describe an experiment to determine the linear expansivity of a steel rod. (ii) Steel bars, each of length 3m at 29°C are to be used for constructing a rail line. If the linear expansivity of steel is \(1.0 \times 10^{-5}K^{-1}\), calculate the safety gap that must be left between successive bars if the highest temperature expected is 41°C.
(c) State three advantages and two disadvantages of thermal expansion of solids.
(a) What is a wave motion?
The equation \(y = A \sin \frac{2\pi}{\lambda} (Vt-X)\) represents a wavetrain in which y is the vertical displacement of a particle at distance X from the origin in the medium through which the wave is travelling. Explain, with the aid of a diagram, what A and \(\lambda\) represent.
(b) (i) Describe an experiment to determine the frequency of a note emitted by a source of sound
(ii) A pipe closed at one end is 1 m long. The air in the pipe is set into vibration and a fundamental note is produced. If the velocity of sound in air is 340ms\(^{-1}\), calculate the frequency of the note
(c) State two differences between a sound wave and a radio wave.
(a) State the laws of electromagnetic induction.
(b) (i) Describe a simple experiment to show how an induced e.m.f, can be produced; (ii) State two factors on which the magnitude of the induced e.m.f. depends
(c) Explain what is meant by the r.m.s. value of an alternating current
(d) (i) If the alternating current is represented by \(I = l_{o} \sin \omega t\), state what the symbol \(I, I_{o}, \omega\) and \(\omega t\)represent.
(ii) Calculate the instantaneous value of such a current, if in a circuit it has r.m.s value of 15.0A when its phase angle is 30°.
(a)(i) Explain the terms: photoelectric emission and threshold frequency; (ii) Einstein's photoelectric equation can be written as \(E = hf - hf_{o}\) What does each of the symbols used in the equation above represent?
(b) Calculate the frequency of the proton whose energy is required to eject a surface electron with a kinetic energy of \(1.97 \times 10^{-16} eV\) if the work function of the metal is \(1.33 \times 10^{-16}eV\). \((1 eV = 1.6 \times 10^{-18}J; h = 6.60 \times 10^{-34}JS)\).
(c) In a photoelectric cell, no electrons are emitted until the threshold frequency of light is reached. Explain what happens to the energy of the light before emission of electrons begins. State one factor that may affect the numbers of emitted electrons.
(d) Explain what is meant by the duality of matter, illustrating your answer with observation phenomena.
