The instantaneous value of the induced e.m.f as a function of time is ε = ε_o sin ωt where ε_o is the peak value of the e.m.f. The instantaneous value of the e.m.f., one quarter of the period is

• A) 0.00
• B) ε_o/4
• C) ε_o/2
• D) ε_o

(a)(i) What is meant by resonance?

(ii) Outline the necessary steps taken in a simple experiment to illustrate top resonance

(iii) Explain why a vibrating tuning fork sounds louder when its stem is pressed against a table top than when held in air.

(b) Explain with the aid of diagrams, how a concave mirror could be used to: (i) Ignite a piece of carbon paper; (ii) produce an exact copy of a picture on a screen.

The operation of an optical fibre is based on the principal of

• A. dispersion of light
• B. interference of light
• C. refraction of light
• D. polarization of light

The change of state from solid to liquid occurs

• A. at constant temperature
• B. when temperature is lower than the boiling point
• C. when temperature is just near freezing point
• D. when temperature is equal to the boiling point

If a current carrying coil is mounted on a metal frame, the back e.m.f. induced in the coil causes

• A. inductance
• B. eddy currents
• C. electro-magnetism
• D. dipole moment

In which of the following transitions is the largest quantum of energy liberated by an hydrogen atom when the electron changes energy levels? [n is the quantum number]

• A. n = 2 to n = 1
• B. n = 1 to n = 2
• C. n = 2 to n = 3
• D. n = 3 to n = 2

A binary operation ⊗ defined on the set of integers is such that m ⊗ n = m + n + mn for all integers m and n. Find the inverse of -5 under this operation, if the identity element is 0

• A) −5/4
• B) −5/6
• C) 0
• D) 5

Which of the following statements about boiling and evaporation at atmospheric pressure is correct?

• A. evaporation and boiling of water take place at 100°
• B. evaporation of water takes place at a temperature greater than 100°C, while boiling takes place at 100°C
• C. evaporation of water takes place at 100°C while boiling takes place at a higher temperature
• D. boiling takes place at 100° while evaporation my take place at temperatures lower than 100°C

A ray of light is incident on a glass block as shown in the diagram below. If the reflected and the retracted rays are perpendicular to each other, what is the refractive index of the glass relative to air.?

• A. 1.65
• B. 1.58
• C. 1.52
• D. 1.48

(a) Explain cations

(b) Draw and label an electrolytic cell.