**UNIVERSITY EXAMINATIONS: 2017/2018**

**EXAMINATION FOR THE DIPLOMA IN INFORMATION TECHNOLOGY**

**CIT102 FOUNDATION PHYSICS AND ELECTRICITY**

**DATE: AUGUST, 2018 TIME: 2 HOURS**

**INSTRUCTIONS: Answer Question 1 AND any other TWO questions.**

**QUESTION ONE (COMPULSORY)**

a) Define the following terms [4 Marks]

(i) Physics

(ii) Electricity

(iii) Distance

(iv) Frequency

b) Briefly describe the following forces when used in physics [4 Marks]

(i) Applied Force

(ii) Gravitational Force

(iii) Normal Force

(iv) Frictional force

c) Briefly explain “ work” as used in physics. Give the mathematical expression too [2 Marks]

d) Differentiate between series and parallel electronic circuits . A neat circuit diagram should be

included [4 Marks]

e) Energy in physics is the capacity for doing work. Explain the two main classifications of energy

[4 Marks]

f) State the SI units for the following [4 Marks]

(i) Current

(ii) Resistance

(iii) Force

(iv) Voltage

g) Define light and state its four properties [5 Marks]

h) State what is meant by the term electromotive force of a cell [1 Mark]

i) Calculate total resistance if four resistors of equal value are connected in series [2 Marks]

**QUESTION TWO**

a) Describe the following branches of physics [6 Marks]

(i) Mechanics

(ii) Geometrical optics

(iii) Atomic Physics

b) A force of 10 Newtons can move an object over a distance of 300 centimeters. Calculate the work

done in newton meters [3 Marks]

c) Define matter and differentiate between the three main states of matter [7 Marks]

D) State the Newton’s first and second laws of motion [4 Marks]

**QUESTION THREE**

a) State any four electronic circuit components [4 Marks]

b) Differentiate between the following electricity concepts [4 Marks]

(i) Protons and electrons

(ii) Conductors and insulators

c) State Ohm’s law [2 Marks]

d) Explain the term “short circuit” and how you could detect it using a multimeter [2 Marks]

e) An electronic circuit comprises of three resistors of 3 Ω, 6Ω and 4Ω connected in parallel across a

12Vd.c power source. Calculate [8 Marks]

(i) The total circuit resistance

(ii) The current from the d.c power source

(iii) The current flowing through each resistor

**QUESTION FOUR**

a) A mathematical relation in physics is a relationship between sets of numbers or sets of elements.

Explain any three mathematical relationships [6 Marks]

b) Briefly explain how energy can be transferred in waves [4 Marks]

c) A force of 200 Newton is exerted on an object of mass 40 kg that is located on a sheet of perfectly

smooth ice.

(i) Calculate the acceleration of the object. [2 Marks]

(ii) If a second object identical to the first object is placed on top of the first object, what

acceleration would the 200 Newton force produce? [2 Marks]

d) State what is meant by electromagnetism [2 Marks]

e) Discus the electromagnetic spectrum and give practical application of these waves in IT

[4 Marks]

**QUESTION FIVE**

a) Differentiate between the following [6 Marks]

(i) Transverse and Longitudinal wave

(ii) Scalar and Vector quantity

(iii) Current and Voltage

b) Briefly explain the operation of any source of electricity. Include any relevant diagrams

[5 Marks]

c) All sources of electricity have internal resistance [5 Marks]

(i) Explain the term “internal resistance of a cell”

(ii) The potential drop (p.d) across the terminals of a cell is 3V when it is not connected to a

circuit and no current is flowing. When the cell is connected to a circuit and a current of

0.37 A is flowing the terminal p.d. falls to 2.8 V. What is the internal resistance of the

cell

d) State what the following electrical instruments will measure [4 Marks]

(i) Ohmmeter

(ii) Voltmeter

(iii) Ammeter

(iv) Multimeter