Right Answer: The thumb rule for determining the current in an AC system is to use the formula: Current (Amps) = Power (Watts) / Voltage (Volts). For tonnage, 1 ton of cooling capacity is approximately equal to 3.517 kW.
Right Answer: Neutral is grounded in an electrical circuit to provide a reference point for voltage, enhance safety by preventing electrical shock, and ensure proper operation of protective devices.
Right Answer: 11kV/440V distribution supply is used for domestic use because it allows for efficient transmission of electricity over long distances with reduced losses, while 440V is suitable for safe and effective distribution to homes and small businesses.
Right Answer: 1. **Vector Group Test**: Connect the transformer to a three-phase supply and measure the phase angles between the primary and secondary windings using a phase sequence indicator or a voltmeter. Compare the measured angles with the expected vector group.
2. **Magnetic Balance Test**: Disconnect the secondary winding and apply a single-phase voltage to one phase of the primary winding. Measure the current in each phase. The currents should be equal if the transformer is balanced. Any significant difference indicates a fault.
3. **Tap Changer Test**: Operate the tap changer through its full range while monitoring the output voltage. Check for smooth operation, correct voltage levels at each tap position, and ensure there are no unusual noises or overheating.
Right Answer: Sensitive Earth fault refers to a low-level earth fault protection system that detects small leakage currents to ground, typically in electrical systems. The effects of a sensitive earth fault can include equipment damage, safety hazards, and potential electrical fires if not addressed promptly.
Ques:- Why the earth pin is thicker than other pins in a plug? Ifit is for reducing resistance, then why the copper earthwire is not so thick as earth pin of socket?
Right Answer: The earth pin is thicker than other pins in a plug to ensure a lower resistance connection and to handle fault currents safely. It also serves as a safety feature, ensuring that the earth connection is made before the live and neutral pins when plugging in. The copper earth wire is not as thick because it is designed to carry the expected fault current, which is typically lower than the current that the earth pin can handle during a fault condition.
Right Answer: Metallic housing is provided for solenoid valves to ensure durability, provide protection against environmental factors, enhance heat dissipation, and improve electromagnetic shielding.
Right Answer: No, you cannot connect a 2.2 kW star motor in delta configuration if it is designed to operate in star. It must be connected in star to function properly.
Right Answer: - **Stator**: The stationary part of a generator that contains the windings and produces electrical output.
- **Rotor**: The rotating part of a generator that creates a magnetic field, inducing voltage in the stator windings.
- **Exciter**: A device that provides the necessary current to the rotor windings to create a magnetic field.
- **Rotating Rectifier**: A component that converts the alternating current (AC) generated in the rotor into direct current (DC) for the excitation system.
Right Answer: Transformers are rated in kVA (kilovolt-amperes) because they are designed to handle both voltage and current without considering the power factor. This rating reflects the apparent power, which is the product of voltage and current, and is independent of the type of load connected to the transformer.
Right Answer: 1. Simplicity of design and control.
2. Easier to store in batteries.
3. No reactive power losses.
4. More efficient for low-voltage applications.
5. Better for electronic circuits and devices.
6. Constant voltage and current levels.
Right Answer: I want to pursue an MBA to enhance my leadership skills, gain a broader understanding of business operations, and improve my ability to make strategic decisions, which will help me advance in my career and contribute more effectively to my organization.
