UNIVERSITY EXAMINATIONS: 2017/2018
EXAMINATION FOR THE DIPLOMA IN INFORMATION TECHNOLOGY
CIT102 FOUNDATION PHYSICS AND ELECTRICITY FOR IT
FULLTIME/PARTTIME
DATE: APRIL, 2018 TIME: 1 ½ HOURS
INSTRUCTIONS: Answer Question 1 AND any other TWO questions.
QUESTION ONE
a) Define the following terms and acronyms as used in physics [5 Marks]
(i) SHM
(ii) voltage
(iii) electricity
(iv) speed
(v) displacement
(vi) potential energy (PE)
b) Explain THREE laws of motion by Newton [6 Marks]
c) Briefly discuss the following types electrical materials [3 Marks]
(i) insulators
(ii) semi-conductors
(iii) conductors
d) State Ohms law and give relevant mathematical expressions of the law [3 Marks]
e) Calculate the following [13 Marks]
(i) The displacement of a body that travels at a constant velocity of 3.5m/s for 1.5 minutes
(ii) The time taken for a rock to reach the bottom of a well if it is 9m deep
(iii) The range of a missile fired at an angle of 45o
at an initial velocity of 26.7m/s over a flat
terrain
(iv) The PE gained by a 34Kg mass when raised to a height of 145cm
(v) The Work done in pushing a 25Kg mass over a displacement of 2.3m. Assume that the
force of friction is 60N
QUESTION TWO
a) Define the terms below [10 Marks]
(i) Free electrons
(ii) atom
(iii) charge
(iv) electric potential difference (pd)
(v) current
b) Calculate the following [10 Marks]
(i) The resistance of a bulb if a 200mA current flows when a 48V battery is connected
across it
(ii) The current flowing in a series circuit that consists of two resistors of 2.3KΩ and
0.98MΩ if a 7.5V source is used
(iii) The current flowing through the 0.98MΩ resistor , if the resistors in Q2b(ii) above are
now connected in parallel
QUESTION THREE
a) Define the following terms [4 Marks]
(i) photon
(ii) wavelength
(iii) frequency
(iv) electromagnetic wave
b) Describe how wavelength and frequency are related to each other [2 Marks]
c) Explain colour of light using wavelength [3 Marks]
d) A wave has a speed of 340m/s. Calculate the frequncy is the wavelength is 12cm [3 Marks]
e) Name the two main types of waves, make sketches and give examples also [5 Marks]
f) Define the term total internal reflection and give an application [3 Marks]
QUESTION FOUR
a) Use a diagram to show the main parts of a circuit. Also indicate the role of each [6 Marks]
b) Explain the meaning of the terms short circuit and open circuit [2 Marks]
c) Explain how an open circuit affects a network cable. Explain how to detect a suspected open circuit
[3 Marks]
d) Explain how a short circuit can be detected between two points. Also give the effects of a short
circuit on a power supply [3 Marks]
e) Give the following function of the following electric meters. In each case sketch a diagram to show
how they are used to take measurements. Mention any precautions to take with each [6 Marks]
(i) The Voltmeter
(ii) The Ohmeter
QUESTION FIVE
a) Give FOUR SI units of measure and the quantities measured [4 Marks]
b) Define derived units using examples [2 Marks]
c) Describe the use of electromagnetic waves in communication [3 Marks]
d) Calculate the current taken by a 90W computer connected to a 240V source. [2 Marks]
e) Suggest a suitable fuse for the computer in Q5d above [2 Marks]
f) Differentiate between reflection and refraction [2 Marks]
g) Give the difference between dc and ac voltage [2 Marks]
h) Give the use of the following electronic devices. For each give a symbol. [3 Marks]
(i) capacitor
(ii) resistors
(iii) transformer
