Narrative ReportWhen an object is immersed in water, it feels lighter. In a cylinder filled with water, the action of inserting a mass in the liquid causes it to displace upward. In 212 B.C., the Greek scientist Archimedes discovered the following principle:an object is immersed in a fluid is buoyed up by a force equal to the weight of the fluid displaced by the object. This became known asArchimede's principle. The weight of the displaced fluid can be found mathematically. The fluid displaced has a weightW=mg. The mass can now be expressed in terms of the density and its volume,m=pV. Hence,W=pVg.

It is important to note that the buoyant force does not depend on the weight or shape of the submerged object, only on the weight of the displaced fluid. Archimede's principle applies to object of all densities. If the density of the object is greater than that of the fluid, the object will sink. If the density of the object is equal to that of the fluid, the object will neither sink or float. If the density of the object is less than that of the fluid, the object will float.Also about resistors, Resistors are "Passive Devices", that is they contain no source of power or amplification but only attenuate or reduce the voltage signal passing through them. This attenuation results in electrical energy being lost in the form of heat as the resistor resists the flow of electrons through it. Then a potential difference is required between the two terminals of a resistor for current to flow. This potential difference balances out the energy lost. When used in DC circuits the potential difference, also known as a resistors voltage drop, is measured across the terminals as the circuit current flows through the resistor. Most resistors are linear devices that produce a voltage drop across themselves when an electrical current flows through them because they obey Ohm's Law, and different values of resistance produces different values of current or voltage. This can be very useful in Electronic circuits by controlling or reducing either the current flow or voltage produced across them.

Post Lab Questions1. Enumerate and describe the common types of resistors. a) Carbon Composition Resistor- Made of carbon dust or graphite paste, low wattage valuesb) Film or Cermet Resistor- Made from conductive metal oxide paste, very low wattage valuesc) Wire-wound Resistor- Metallic bodies for heatsink mounting, very high wattage ratingsd) Semiconductor Resistor- High frequency/precision surface mount thin film technology2. Describe the following instruments and devices as to their functions and give their electrical symbols: Multimeter, DC ammeter, DC Voltmeter, Fix Resistors, Variable Resistors, Galvanometer, Capacitors, and Rectifier.MultimeterResistor and Capacitor Multimeters are tools used to troubleshoot electrical and electronic circuits. They are also used to check voltages to ensure correct operating levels. The most common models measure voltage, current and resistance. More expensive models can also measure capacitance and inductance.

RectifierRectifier, Semiconductor

Rectifier, Silicon-Controlled

Rectifier, Tube-Type

Arectifieris an electrical device that convertsalternating current(AC), which periodically reverses direction, todirect current(DC), which flows in only one direction. The process is known asrectification. Physically, rectifiers take a number of forms, includingvacuum tubediodes,mercury-arc valves,solid-statediodes,silicon-controlled rectifiersand other silicon-based semiconductor switches. Historically, even synchronous electromechanical switches and motors have been used. Early radio receivers, calledcrystal radios, used a "cat's whisker" of fine wire pressing on a crystal ofgalena(lead sulfide) to serve as a point-contact rectifier or "crystal detector".

ComponentCircuitSymbolFunction of Component

VoltmeterA voltmeter is used to measure voltage.The proper name for voltage is 'potential difference', but most people prefer to say voltage!

AmmeterAn ammeter is used to measure current.

GalvanometerA galvanometer is a very sensitive meter which is used to measure tiny currents, usually 1mA or less.

VariableResistor(Rheostat)This type of variable resistor with 2 contacts (a rheostat) is usually used to control current. Examples include: adjusting lamp brightness, adjusting motor speed, and adjusting the rate of flow of charge into a capacitor in a timing circuit.

VariableResistor(Potentiometer)This type of variable resistor with 3 contacts (a potentiometer) is usually used to control voltage. It can be used like this as a transducer converting position (angle of the control spindle) to an electrical signal.

VariableResistor(Preset)This type of variable resistor (a preset) is operated with a small screwdriver or similar tool. It is designed to be set when the circuit is made and then left without further adjustment. Presets are cheaper than normal variable resistors so they are often used in projects to reduce the cost.

CapacitorA capacitor stores electric charge. A capacitor is used with a resistor in a timing circuit. It can also be used as a filter, to block DC signals but pass AC signals.

Capacitor, polarisedA capacitor stores electric charge. This type must be connected the correct way round. A capacitor is used with a resistor in a timing circuit. It can also be used as a filter, to block DC signals but pass AC signals.

Fix ResistorA resistor restricts the flow of current, for example to limit the current passing through an LED. A resistor is used with a capacitor in a timing circuit.Some publications still use the old resistor symbol:

3. Enumerate some preliminary precautions before using a multimeter, DC Voltmeter, and DC ammeter. Multimeter

Warning! Do not reverse battery polarity use only: red clamp to positive (+) black clamp to battery negative (-) preliminary precautions & setup3.1 avoid damage from shortingEnsure that power switch is set to off to avoid damage to the ti. ensure that the alligator clamps are separated and secured so that short circuit does not exist when the ti is turned on.3.2 connect to appropriate ac sourceConnect the auxiliary equipment and the ti to the appropriate power source. (120v 50/60hz 10a)

VoltmeterNOTE: Unless otherwise specified, verify the results of each test and take corrective action whenever the test requirement is not met Before proceeding.4.1 VOLTMETER TestsVoltmeter tests performed WITHOUT BATTERY or LOAD BANK CONNECTED.4.1.1 Set Conditioner switchSet switch on C25C, located at the bottom of front panel, to ON position.4.1.2 Verify voltage readingTI voltmeter reads approximately 21 Volts.

AmmeterWARNING Current & Voltages Harmful currents and voltages may be present in the ti dc battery cable leads. the ti on/off/reset switch must be set to the off/reset position before connecting or disconnecting the ti dc battery cable to/from the battery.4.1.6 AMPERE METER TESTSNote: The TI ammeter is connected to an internal shunt in the TI. Shunts are large blocks of copper connectors and copper alloy resistor bars. They dont lose accuracy unless subjected to prolonged overload above 50 Amps, which the C25C is not capable of producing. Therefore 2 options are described. Option 1: Verifying TI shunt and ammeter. Option 2: Verifying the TI ammeter only with the TIs internal shunt.