WTMA - Wiesen Test of Mechanical Aptitude Basic Electrical Principles Questions and Answers — Questions and Answers
Question 1: In a simple electrical circuit, if the voltage is doubled and the resistance remains constant, what happens to the current?
- It is halved.
- It is quadrupled.
- It doubles. (Correct answer)
- It remains the same.
Correct answer: It doubles.
According to Ohm's Law (V=IR, or I=V/R), current (I) is directly proportional to voltage (V) and inversely proportional to resistance (R). If the voltage is doubled while resistance stays the same, the current must also double to maintain the relationship.
Question 2: Which of the following materials is the best electrical insulator?
- Copper
- Rubber (Correct answer)
- Aluminum
- Steel
Correct answer: Rubber
An electrical insulator is a material in which electric current does not flow freely. Rubber is an excellent insulator, while materials like copper, aluminum, and steel are conductors because they allow electricity to pass through them easily.
Question 3: Imagine two light bulbs are connected in a series circuit to a battery. If one of the light bulbs burns out (the filament breaks), what will happen to the other light bulb?
- It will get brighter.
- It will get dimmer.
- It will stay the same brightness.
- It will go out. (Correct answer)
Correct answer: It will go out.
In a series circuit, there is only one path for the current to flow. If one bulb burns out, the filament breaks, creating an open circuit. This stops the flow of current entirely, and the other bulb will also go out.
Question 4: What is the primary function of a resistor in an electronic circuit?
- To store electrical energy
- To increase the flow of current
- To control or limit the flow of current (Correct answer)
- To generate voltage
Correct answer: To control or limit the flow of current
A resistor is a passive electrical component with a specific electrical resistance. Its main purpose in a circuit is to reduce current flow, adjust signal levels, divide voltages, and terminate transmission lines, among other uses.
Question 5: In a parallel circuit with three resistors of different values connected to a voltage source, which of the following statements is true?
- The current is the same through all three resistors.
- The voltage across each resistor is the same. (Correct answer)
- The total resistance is the sum of the individual resistances.
- The power dissipated by each resistor is identical.
Correct answer: The voltage across each resistor is the same.
A key characteristic of a parallel circuit is that the voltage is the same across all components. The current divides among the different branches, with less current flowing through branches with higher resistance. The total resistance is calculated differently than in a series circuit and is always less than the smallest individual resistor.
Question 6: Electrical power is most commonly measured in which unit?
- Volts
- Amperes
- Ohms
- Watts (Correct answer)
Correct answer: Watts
Watts (W) are the standard unit of electrical power. Power is the rate at which electrical energy is transferred. Volts measure electrical potential difference, Amperes (Amps) measure current, and Ohms measure resistance.
WTMA - Wiesen Test of Mechanical Aptitude Basic Electrical Principles Questions and Answers
In a simple electrical circuit, if the voltage is doubled and the resistance remains constant, what happens to the current?