Manufacturing Practices (BT-106) - Important Questions

Explain the principles of basic electrical safety in a manufacturing laboratory. Your answer should cover personal protective equipment (PPE), grounding and earthing, isolation and lockout-tagout procedures, safe work clearances, and emergency response for electrical accidents.

Describe in detail how to use a digital multimeter to measure DC voltage ($V$), AC voltage, current ($I$) and resistance ($R$). Include meter range selection, lead connections, polarity considerations, precautions to avoid damaging the instrument, and common sources of measurement error.

With a labeled diagram, explain the working principles of a Cathode Ray Oscilloscope (CRO) or digital storage oscilloscope. Describe probe compensation, triggering modes, time base and vertical sensitivity controls, and typical measurements that require an oscilloscope rather than a multimeter.

A resistor in a circuit shows a voltage drop of $V=12\ \mathrm{V}$ when the measured current is $I=2\ \mathrm{A}$. Calculate the resistance value and state the correct multimeter function and range you would use to measure this resistance reliably. Show the calculation using Ohm's law.

Describe wiring practices, circuit assembly steps and a systematic troubleshooting procedure for a simple single-phase control circuit used in a manufacturing setup. Include common faults, diagnostic checks using test equipment, and remedial actions.

List the common electronic components encountered in workshop diagnostics (resistors, capacitors, inductors, diodes, transistors, ICs). For each component, describe the standard bench test using a multimeter or appropriate test equipment and state the expected measurement outcomes for a healthy component.

Explain a step-by-step procedure to test a silicon diode using a digital multimeter. State the expected forward voltage reading and the expected reverse-bias reading (open or leakage), and describe how to interpret the results to decide if the diode is good or faulty.