Amazon Control Systems Tech / Lead Assessment [2024]

The correct answer is A.

Answer choices C and D cannot be true because M2 is not affected.

In this circuit, the forward button is an in-parallel auxiliary connection with M1. This means the forward switch enables M1.

However, when the forward button is released, the M1 connection maintains the current and keeps energizing the forward circuit.

The correct answer is A.

The Manchester code is a type of line code used for data encoding. It encodes data bits as follows:

• High (1) – high (1), then low (0)
• Low (0) – low (0), then high (1)

This encoding can also be opposite (i.e. High is encoded as low, then high, and vice versa), depending on the convention.

Since the Manchester code uses only two phases (0) and (1), separated by 180 degrees, it is a type of binary phase-shift keying (BPSK).

The correct answer is B.

SPDT is a single pole double throw relay. The schematic diagram of an SPDT is shown below.

There are three terminals:

• COM (common)
• NO (normally open)
• NC (normally closed).

When the relay is OFF, the COM terminal is connected with the NC terminal and when the relay is ON, the COM terminal is connected with the NO terminal. The schematic diagram of SPST (single pole single throw) and DPDT (double pole double throw) are also shown below.

The correct answer is B.

A solenoid is an actuator constructed of a high permeability core inside a conductive helix. When current flows through the helix, the core is induced with a magnetic field causing it to move and actuate the device. In order to return to an un-actuated position, the solenoid requires a spring or a different external force.

When the solenoid requires additional force, a higher current may be used to generate a more potent magnetic field. Reducing the permeability of the core will result in a lower magnetic field. The strength of the spring return has no effect on the actuating force of the solenoid.

The correct answer is A.

Below are the steps of analysis:

The correct answer is C.

The minimal fuse rating should be higher than the normal operating current of the system. Since an electrical system is connected in parallel, the total current in the system when all three appliances are working is the sum of all three.

The current consumption of each appliance is calculated by:

I = P/V

Where:

• I = Current [Ampere]
• P = Power [Watt]
• V = Voltage [Volt]

Therefore:

• Appliance A consumes 550/110 = 5A
• Appliance B consumes 770/110 = 7A
• Appliance C consumes 330/110 = 3A

The total current in the system is 5 + 7 + 3 = 15A

In order to withstand normal working conditions, the minimal fuse amperage rating must be greater than 15A, thus 20A.

The correct answer is B.

Induction motors which are also called asynchronous motors work on the principle of induction which is inducing a current in the rotor by changing the magnetic field of the stator.

We can differentiate two definitions of speed in induction motors:

• Synchronous speed – The speed of the changing magnetic field.
• Asynchronous speed – The speed of the rotor (which is different from the synchronous speed).

The difference between these two is called slip. Therefore, B is the correct choice.

As for the other answers, single phasing (A) occurs when one of the motor terminals is loose or disconnected making the motor run on a single-phase. No-load speed of a motor (C) is the maximum speed of a motor when there is no load applied.

The correct answer is D.

Teach pendants are devices used for programming the application of industrial robots. They are usually provided as an integral component of the robot as a whole. They are considered one of the most fundamental types of robot HMI (Human Machine Interface).