Unit 12 Review

How do you find Watts?

How do you find Watts?

Multiply voltage by current

What is the difference between series and parallel?

In a series circuit, all loads are wired in a single series keeping current constant, while in parallel, loads are wired parallel to each other, keeping voltage constant.

What is the difference between positive and negative charges and how they act?

Like charges repel and opposites attract negative always goes to positive

What is the difference between insulators and conductors

Conductors allow the movement of electrons, while insulators do not

What is Ohm’s law

E/I*R or P/I*E

What is the difference between voltage, current, and resistance, and their properties

Voltage is electromotive force/pressure, current is the intensity of electron movement, resistance is the opposition to electrical current flow

What happens to current in a circuit if the resistance is increased?

Current decreases

What happens to resistance of a parallel circuit if more loads are added?

Resistance decreases

What happens to the magnetic field around a wire if it is formed into a coil?

The magnetic field becomes greatly intensified

What is 1kW of electrical energy equal to?

1000 Watts

If the diameter of a wire is increased what happens to the resistance?

As diameter increases, resistance decreases

How do you check a diode with a meter?

One way it will show resistance, but the other way it will show OL

How do you calculate total resistance of a parallel circuit?

Do not add, make parallel circuit into a series circuit first

What is the unit of measurement for a capacitor?

Microfarad

How do you calculate 2 or more resistances in series?

Add the resistances together to find total resistance

If 3 bulbs are wired in parallel and one bulb burns out, does the total current decrease?

True, decreases

What is the main purpose of a rectifier?

A rectifier converts AC to DC

What is the purpose of a heat sink?

A heat sink provides more surface area for heat to dissipate from somewhere that heat needs to be dispelled from.

How are copper wire sizes measured?

Gauges measures in circular mils

What is a PTC thermistor?

Positive Temperature Coefficient thermistors increase in resistance with increase in temperature

Ohm meters are only to be used on circuits that are deenergized (T/F)

T