EIAT - Elevator Industry Aptitude Basic Electrical Principles Questions and Answers — Questions and Answers
Question 1: A technician measures a voltage of 24 VDC across a resistor with a resistance of 8 ohms. According to Ohm's Law, what is the current flowing through the resistor?
- 192 A
- 0.33 A
- 3 A (Correct answer)
- 32 A
Correct answer: 3 A
Ohm's Law states that Current (I) = Voltage (V) / Resistance (R). In this scenario, I = 24V / 8Ω, which equals 3A.
Question 2: In a simple series circuit containing three light bulbs, which of the following statements is true about the electric current?
- The current is divided equally among the three bulbs.
- The current is the same through all three bulbs. (Correct answer)
- The current is highest at the first bulb and lowest at the last.
- The total current is the sum of the current in each bulb.
Correct answer: The current is the same through all three bulbs.
A primary characteristic of a series circuit is that it provides only a single path for the current to flow. Therefore, the amount of current is constant at all points throughout the circuit.
Question 3: An elevator's door motor operates on a 120V AC circuit and draws a current of 2 amps. How much power does the motor consume?
- 60 Watts
- 122 Watts
- 0.016 Watts
- 240 Watts (Correct answer)
Correct answer: 240 Watts
Electrical power (P, in Watts) is calculated by multiplying voltage (V) by current (I). Therefore, P = 120V * 2A = 240W.
Question 4: If two components in an elevator's control panel are wired in parallel to a 24V DC power source, what is the voltage across each component?
- 24V across each (Correct answer)
- 12V across each
- 48V total across both
- It depends on the resistance of each component.
Correct answer: 24V across each
In a parallel circuit, all components are connected across the same two points of the circuit. This means that the voltage across each component is the same as the source voltage.
Question 5: What is the primary characteristic that distinguishes Alternating Current (AC) from Direct Current (DC)?
- AC has a higher voltage than DC.
- The flow of current is constant in one direction in AC.
- DC can only be used for low-power devices.
- The direction of current flow periodically reverses in AC. (Correct answer)
Correct answer: The direction of current flow periodically reverses in AC.
The fundamental difference is that Direct Current (DC) flows in a single, constant direction, while Alternating Current (AC) periodically reverses its direction of flow.
Question 6: A technician is troubleshooting a circuit that keeps shutting off. They find a device designed to open the circuit automatically if the current becomes excessive. What is the primary function of this device?
- To increase the voltage in the circuit.
- To protect the circuit from overcurrent conditions. (Correct answer)
- To store electrical charge for later use.
- To convert AC to DC.
Correct answer: To protect the circuit from overcurrent conditions.
Devices like fuses and circuit breakers are overcurrent protection devices. Their function is to interrupt the flow of electricity (open the circuit) when the current exceeds a safe level, protecting wiring and components from damage.
EIAT - Elevator Industry Aptitude Basic Electrical Principles Questions and Answers
A technician measures a voltage of 24 VDC across a resistor with a resistance of 8 ohms.
According to Ohm's Law, what is the current flowing through the resistor?