Bridge devices

Definition

Bridge devices are electrical circuits used to measure unknown resistances, capacitances, and inductances through null measurements. They achieve balance by adjusting known components until no current flows through the detection element.

5 Must Know Facts For Your Next Test

1. The Wheatstone bridge is the most common type of bridge device for measuring resistance.
2. A balanced bridge occurs when the ratio of two resistors in one branch is equal to the ratio of two resistors in another branch.
3. Null measurement refers to the condition where the detector shows zero deflection, indicating balance.
4. Bridge devices can be used to measure small changes in resistance with high precision.
5. In AC bridges, both magnitude and phase must match for balance to occur.

Review Questions

• What condition must be met for a bridge device to be considered balanced?
• How does a Wheatstone bridge measure an unknown resistance?
• Why are null measurements important in the operation of bridge devices?

Related terms

Wheatstone Bridge: An electrical circuit used to precisely measure an unknown resistance by balancing two legs of a bridge circuit.

Null Measurement: A technique where adjustments are made until a detector indicates zero current or voltage, signifying a balanced state.

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