MGVCL Exam Paper (30-07-2021 Shift 3)
The miniature circuit breaker (MCB) with ____ trip characteristics trips instantaneously when the current flowing through it reaches between 10 to 20 times the rated current.
Type B MCB: Type B devices are generally suitable for domestic applications. They are designed to trip at fault currents of 3 - 5 times rated current.
Type C MCB: Type C devices are the normal choice for commercial and industrial applications These devices are designed to trip at 5 - 10 times rated current
Type D MCB: The Type D devices have more limited applications, normally in industrial use where high inrush currents may be expected. Type D devices are designed to trip at 10 - 20 times.
Bus Type - Known Parameter - Unknown Parameter Load Bus -P, Q - V, phase angle Generator Bus - P, V (magnitude) - Q, Voltage phase angle Slack Bus Voltage - magnitude and phase angle - P, Q
A coil having large number of turns of fine wire is wound on the middle limb of the shunt magnet. This coil is known as pressure or voltage coil and is connected across the supply mains. The voltage coil produces a high ratio of inductance to resistance.
A remote terminal unit (RTU) is a microprocessor-controlled electronic device that interfaces objects in the physical world to a distributed control system or SCADA (supervisory control and data acquisition) system by transmitting telemetry data to a master system and by using messages from the master supervisory. This is accomplished by transmitting telemetry data to the system and/or changing the physical state of connected objects based on control messages received from the automation system. It is used to interface field devices with SCADA. RTUs can support multiple communication protocols at the same time. A limited number of input and output devices can be added to it.
EXAMIANS