DGCA CAR 66 MODULE 3 P-03, 06. DC CIRCUIT 07a. Resistance/Resistor. 07b. Resistance/Resistor. 08. Power. 09. Capacitance/capacitor. 10a. Magnetism. 10b. Magnetism.

PART 66 Module 3 ELECTRICAL FUNDAMENTAL

3.6 DC Circuits -

1. Ohms Law, Kirchoff's Voltage and Current Laws; 
2. Calculations using the above laws to find resistance, voltage and current; 
3. Significance of the internal resistance of a supply. 

3.7 Resistance/Resistor(a) Resistance and affecting factors;

1. Specific resistance; 
2. Resistor colour code, values and tolerances, preferred values, wattage ratings; Resistors in series and parallel;
3. Calculation of total resistance using series, parallel and series parallel combinations; Operation and use of potentiometers and rheostats;
4. Operation of Wheatstone Bridge. 

3.7 (b)

1. Positive and negative temperature coefficient conductance; 
2. Fixed resistors, stability, tolerance and limitations, methods of construction; 
3. Variable resistors, thermistors, voltage dependent resistors; 
4. Construction of potentiometers and rheostats; 
5. Construction of Wheatstone Bridge; 

3.8 Power

Power, work and energy (kinetic and potential);
Dissipation of power by a resistor;
Power formula;
Calculations involving power, work and energy.

3.9 Capacitance/Capacitor

1. Operation and function of a capacitor; 
2. Factors affecting capacitance area of plates, distance between plates, number of plates, dielectric and dielectric constant, working voltage, voltage rating; 
3. Capacitor types, construction and function;
4. Capacitor colour coding; 
5. Calculations of capacitance and voltage in series and parallel circuits; 
6. Exponential charge and discharge of a capacitor, time constants; 
7. Testing of capacitors. 

3.10 Magnetism
(a) Theory of magnetism;

1. Properties of a magnet 
2. Action of a magnet suspended in the Earth's magnetic field; 
3. Magnetisation and demagnetisation; 
4. Magnetic shielding; 
5. Various types of magnetic material; 
6. Electromagnets construction and principles of operation; 
7. Hand clasp rules to determine: magnetic field around current carrying conductor. 

3.10(b)

• Magnetomotive force, field strength, magnetic flux density, permeability, hysteresis loop, retentivity, coercive force reluctance, saturation point, eddy currents; 
• Precautions for care and storage of magnets.

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