Electricity- MTE 508 Prof. Pasamon

in the world ofELECTRICITY : 

in the world ofELECTRICITY

Ohm : 

Ohm ● unit of electrical resistance (Ω)

Resistance : 

Resistance ● property of any object or substance to resist or opposed the flow of electricity.

Current : 

Current is the electron flown in an electric circuit.

Voltage : 

Voltage ●is the force that pushes the circuit to flow.

Ohm’s Law : 

Ohm’s Law ●state that current is directly proportional to voltage and inversely proportional to the resistance.

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WHERE: I- Current E- Voltage Ω- Resistance

FORMULA: : 

FORMULA: E= I x R I= E/R R= E/I

Simple circuit: : 

Simple circuit:

PROBLEM: : 

PROBLEM: 1. Find the resistance in the given circuit diagram. V-24 I-1.5 R-?

Given: : 

Given: E-25V I- 1.5 amp. R- ?

Solving: : 

Solving: R=E/I =24 V 1.5 amp. R=16 Ω

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2. If a 20-ohm tape recorder is plug to a 220-volt power source, how many amperes will it draw?

Given: : 

Given: R- 20 Ω E- 220 V I- ?

Solving: : 

Solving: I=E/R = 220 V 20Ω I= 11 amp.

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3. A public address system is connected to a 22o-volt convenience outlet and draw 10 amperes. What is the resistance of the amplifier?

Slide 17: 

Given: E= 220 V I = 10 amp. R=?

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Solving: R=E/I =220 V 10 amp. R= 22 Ω

Series circuit : 

Series circuit A series electrical circuit is one which total line current passes through each and every conductor in the circuit

Law of series circuit : 

Law of series circuit The first law states that the individual resistance in a series circuit add up to the total circuit resistance. RT= R1+R2+R3+...Rn ● The second law states that the current has the same value at any point within a series circuit. IT= I1=I2=I3=...In ●The third law states that the individual voltage across the resistor in a series circuit add up to the total voltage applied to that circuit ET= E1+E2+E3+...En

Sample problem : 

Sample problem In a simple circuit, find the power dissipate by a 10Ω resistor when the current flowing through it is 5 amperes. Required: Power (P) solution: P=I2 x R = (54 x 54) x 10Ω = 250 watts

Parallel circuit : 

Parallel circuit A parallel electrical circuit is one which current may flow through two or more independent branched Two or more components are considered in parallel if the same voltage appears across all these components

Law of parallel circuit : 

Law of parallel circuit The total voltage of a parallel circuit is the same across each branch of the circuit ET= E1=E2=E3=...En ●The total current in a parallel circuit is equal to the sum of the individual branch current. IT=I1+I2+I3+...In ●The total resistance in a parallel circuit ia always less or approximately equal to the value of the smallest resistive branch. 1 = 1 + 1 + 1 + ... 1 RT R1 R2 R3 Rn

Sample problem : 

Sample problem Three resistance of 30 ohms, 60 ohms, and 80 ohms are connected in parallel. If the current through the 30 ohms resistor is 8 amperes, find the current through the 60 ohms and 80 ohms resistor. Given: R1=30Ω R2= 60Ω R3= 80Ω

Solution : 

Solution Required: I1 and I2 E1 = I1 . R1 E1 = 8 (30) = 240 volts Since; ET=E1=E2=E3=...En= 240 volts 240V = I2 (60) I2 = 240V = 4 amperes 60Ω 240V = I3 (80) I3= 240V= 3 amperes 80Ω

Complex circuit : 

Complex circuit It is a combination of series and parallel circuit. This circuit consist of a number of minor circuit that are connected in series while other parts of the circuit are connected in parallel or a series- parallel circuit which comprise a series connection of the number of multiple circuit. Whenever two or more components of an electrical network are in parallel, all the character of parallel circuit must be applied to these components, and whenever two or more components are in series, all characteristic must be applied.

MULTIPLE CHOICE: : 

MULTIPLE CHOICE: Direction: Choose the best answer; write the letter of the correct answer on the space provided. ____ 1. What is the electron flown in an electric circuit,this is measured in unit called ampere (I) a. Current c. Resistance b. Voltage d. Circuit

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____ 2. Is the opposition to the flow of electric current, also measured in ohm (Ω) a. Current c. Resistance b. Voltage d. Circuit ____3. Is a path where current can flow through. a. Electricity c. Electric Circuit b. Ohm’s Law d. Resistance

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____4. States that current is directly proportional to voltage and inversely proportional to the resistance. a. Ohm’s b Law b. Electric Circuit c. Resistance d. Current ____5. Is the force that pushes the circuit to flow. a. Voltage c. Resistance b. Current d . Electricity

KEY TO CORRECTION : 

KEY TO CORRECTION 1. a 2. c 3. c 4. a 5. a

Slide 31: 

ASSIGNMENT: Topic: 1. What is Series Circuit? 2. What is Parallel Circuit? Reference: Fundamentals of Basic Electricity.

Slide 32: 

Prepared By: Dinavie M. Cangco MTE - 508