PHYSICS

2nd November, 2016

Ankit R Patel

apatel@uj.edu.sa

Department of Electrical & Computer Engineering

University of Jeddah, Kingdom of Saudi Arabia

Index

• Overview of Exam

• Exam Structure

• Overview of Physics

Overview of Exam This engineering exam is planned by the ministry of higher education andadministrated by Qiyas center.

It is aimed at examining engineering students in all Saudi Engineering Collegesin their last year of study.

The exam is Multiple Choice Questions (MCQs) and is divided into two sessions:A Morning Session, devoted to General Skills and General Engineering; andEvening Session, devoted to disciplines of engineering.

The exam tests the students in the General Skills and also in the four keylearning areas:

1. Basic Sciences and Engineering Fundamentals

2. Engineering Analysis and Investigation

3. Engineering Design

4. Engineering Practice

Exam StructureEligibility for Exam: Bachelor degree holders in engineering and those who are inthe final year of such program are eligible.

Exam Structure: The exam consists of two sessions (3 hours each) during one day(one morning session and the other in afternoon) with two hours break betweenthe two sessions.

Session:1 The 3 hours morning session consists of 1 hour (44 questions) forGeneral Skills and 2 hours (60 questions) for General Engineering Skills.

Session:2 The 3 hours evening session devoted to related engineering branchdiscipline. The session consists of 50 questions carrying a maximum of 100marks.

Note: Both sessions have MCQs type questions.

Exam Structure conti…

The General Skills consists of:

Communications Skills

Numeracy and Calculation Skills

Computer Literacy Skills

Interpersonal Skills

Problem Solving Skills

Learning & Performance Improvement Skills

Exam StructureThe General Engineering Skills consists of:

Mathematics

Numerical Techniques

Probability & Statistics

Physics

Statics & Dynamics

Electricity & Magnetism

Chemistry

Thermodynamics

Fluid Mechanics

Material Science

Engineering Drawing

Process Economics

Project Management

Codes, Ethics, Environment & Social Issues…

Exam Structure conti…

Exam StructureExam Type:

The exam is paper based and all questions are multiple choice questions. Each question has 4 choice for the answer. There is no negative marking for wrong answers.

Exam Rules:

• Books, Lecture notes, or another type of material are not allowed in the exam.

• Approved calculators are allowed to do the necessary calculations.

• Admission in the examination center will be only through authorities admit card issued by examination authority.

• Necessary reference sheets, monographs, equations and/or relevant data will be provided during the exam.

Exam Structure conti…

Exam Structure

“Physics explains the world around us by identifyingmeaningful relationship that characterize nature –relationships which are evaluated in terms of physicalquantities.”

Generally a physical quantity is simply anything to which we can assigna precise numerical value, via some sort of measurement. Note thatthe particular values taken by physical quantities are not whatmatters most; in physics, we are interested in how the quantities arerelated to one another.

What is Physics ?

Exam StructureEvery measurable quantity has a unique physical dimension associated with it. ::For Example:The height of the buildingThe distance from Jeddah to University of JeddahThe thickness of piece of paperThese all are in the category of Length [L].

:: Time intervals, timestamps, or any other measurement characterizing duration,all comes in the category of Time [T].

:: Another unit to be measurement is Mass [M].

Remember:: Length[L], Time[T], Mass[M]

Physical Quantities and Dimensional Analysis

Exam StructurePhysical Quantities and Dimensional Analysis conti…

Exam StructureMotion Analysis

Exam Structure

With Newton’s Laws we begin the study of how motion occurs in the real world.The study of the causes of motion is called dynamics, or mechanics.

The study of Newton’s laws and their implications is often called Newtonian orclassical mechanics.

First Law of Newton:

Newton’s Laws

Exam StructureSecond Law of Newton:

This laws gives relations between the net Force (F) acting on a mass m and itsacceleration a.

Newton’s Laws conti…

Exam StructureThird Law of Newton:

This law is popularly stated as the “law of action and reaction”, but in fact it dealswith the forces between two objects.

Newton’s Laws conti…

Exam StructureOhm found experimentally in 1825 that for a given piece of wire, the current,

labeled I, was directly proportional to the applied voltage (number of batterycells) V, and wrote it as I =V/R, where V is in volts, I in amps.

“R” is called the resistance of the wire, and is measured in ohms: one volt sendsone amp through one ohm.

Ohm’s Law

V

I

R

These are the standard symbols for a battery and a resistance: remember the standard “current” is really electrons flowing the other way!

Exam Structure• Remember voltage is a measure of potential energy of electric charge, and if one

coulomb drops through a potential difference of one volt it loses one joule of potentialenergy.

• So a current of I amps flowing through a wire with V volts potential difference betweenthe ends is losing IV joules per sec.

• This energy appears as heat in the wire: the electric field accelerates the electrons,which then bump into impurities and defects in the wire, and are slowed down to beginaccelerating again, like a sloping pinball machine.

• Using Ohm’s law, we can write the power use of a resistive heater (or equivalentdevice, such as a bulb) in different ways:

The unit is watts, meaning joules per second.• Electric meters measure total energy usage: adding up how much power is drawn for

how long, the standard unit is the kilowatt hour:1 kWh = 1,000x3,600J = 3.6MJ

Electrical Power

2 2 /P IV I R V R

Exam Structure

A changing magnetic flux through a loop generates an emf around the loop whichwill drive a current. The emf can be written:

Example: Transformer

Faraday’s Law

loop

BdE d

dt

E

Thank you !!!