Examkin

Question

Difficulty: EasySwitches and Relays

Match each switch configuration and electromechanical relay component with its primary function.

  • SPST SwitchControls a single electrical path with basic on-off operation
  • SPDT SwitchDirects current from one common terminal to one of two different output paths
  • Relay CoilGenerates a magnetic field when energized to mechanically move the internal armature
  • Normally Open (NO) ContactMaintains an open circuit in its resting state and conducts only when energized

Answer

SPST Switch matches with basic single-circuit on-off operation; SPDT Switch matches with directing one common terminal between two output paths; Relay Coil matches with generating a magnetic field to move the armature; Normally Open (NO) Contact matches with maintaining an open circuit until energized.
Each component is correctly matched to its defined operational role: an SPST switch opens or closes one path; an SPDT switch alternates between two paths; a relay coil uses current to create an electromagnetic field; and an NO contact stays open until coil actuation occurs.

Step-by-Step Solution

1
Analyze switch pole and throw designations.
SPST (Single Pole, Single Throw) has one input and one output for simple on/off control. SPDT (Single Pole, Double Throw) routes one input to either of two outputs.
Poles define the number of separate circuits controlled, while throws define the number of output positions available per pole.
2
Analyze relay component functions and contact resting states.
The coil provides electromagnetic force to actuate the switch mechanism, while Normally Open contacts only close and allow current flow when this magnetic force is active.
Relay contacts are designated based on their state when the control coil is unpowered (de-energized).

Key Concept

Switch Nomenclature and Electromechanical Relay Operation
Estimated Time:45s
Rate this question

Topics

Switches and Relays

More questions from this topic