Electric Tech Unit Test Study Guide

What is Ohm's Law used to calculate?

• Power

• Resistance

• Voltage

• Current

Answer explanation

Ohm's Law states that current (I) is equal to voltage (V) divided by resistance (R). It is primarily used to calculate the current flowing through a circuit when voltage and resistance are known.

In a parallel circuit, how is the total resistance calculated?

• Sum of individual resistances

• Product of individual resistances

• Inverse of the sum of the inverses of individual resistances

• Average of individual resistances

Answer explanation

In a parallel circuit, total resistance is calculated using the formula: 1/R_total = 1/R1 + 1/R2 + ... + 1/Rn. This means the total resistance is the inverse of the sum of the inverses of individual resistances.

What is the formula for calculating power in Watt's Law?

• (P = I × V)

• (P = I + R)

• (P = V - I)

• (P = R × I)

Answer explanation

The correct formula for calculating power in Watt's Law is P = I × V, where P is power in watts, I is current in amperes, and V is voltage in volts. This formula shows that power is the product of current and voltage.

Which of the following is true about a series circuit?

• Voltage is the same across each component

• Current is the same through each component

• Total resistance is the inverse of the sum of the inverses of individual resistances

• All components have different currents

Answer explanation

In a series circuit, the same current flows through each component, making the second choice correct. Voltage varies across components, total resistance is the sum of individual resistances, and all components have the same current.

What is the primary function of a multimeter?

• To measure temperature

• To measure electrical properties like voltage, current, and resistance

• To amplify sound

• To store electrical energy

Answer explanation

The primary function of a multimeter is to measure electrical properties such as voltage, current, and resistance, making it an essential tool for electrical diagnostics and troubleshooting.

Which material is a good conductor of electricity?

• Rubber

• Plastic

• Copper

• Wood

Answer explanation

Copper is a metal known for its excellent electrical conductivity, making it a good conductor of electricity. In contrast, rubber, plastic, and wood are insulators and do not conduct electricity well.

What does a Van de Graaff generator produce?

• Radio waves

• Static electricity

• Solar energy

• Magnetic fields

Answer explanation

A Van de Graaff generator produces static electricity by accumulating electric charge on its metal dome, which can then be discharged, creating high voltage and sparks.

What are ions?

• Atoms with a neutral charge

• Atoms without electrons

• Atoms with a positive or negative charge

• Atoms without protons

Answer explanation

Ions are defined as atoms that have gained or lost electrons, resulting in a positive or negative charge. Therefore, the correct choice is 'Atoms with a positive or negative charge', as neutral atoms do not qualify as ions.

What is the role of neutrons in an atom?

• To give the atom its charge

• To maintain the atom's mass

• To define the atom's identity

• To conduct electricity

Answer explanation

Neutrons contribute to the atom's mass by adding to the total number of nucleons in the nucleus. While they do not affect the charge or identity of the atom, they are essential for its overall mass.

What is an algorithm?

• A step-by-step procedure for calculations

• A type of computer hardware

• A type of electrical circuit

• A method of storing data

Answer explanation

An algorithm is defined as a step-by-step procedure for calculations, making it essential for problem-solving in computing. The other options do not accurately describe what an algorithm is.