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Zorluk: OrtaDiodes

An electronics technician uses an ohmmeter to test an unmarked semiconductor diode. When the positive lead is placed on Terminal 1 and the negative lead on Terminal 2, the meter indicates a low resistance. When the meter leads are reversed, the meter indicates infinite resistance (an open circuit). Based on these test results, which of the following conclusions is correct?

  1. Terminal 1 is the anode, Terminal 2 is the cathode, and the diode is operational.Cevap
  2. B
    Terminal 1 is the cathode, Terminal 2 is the anode, and the diode is operational.
  3. C
    The diode is defective with an internal short circuit because it conducts current during testing.
  4. D
    The diode is defective because a healthy component must maintain equal bidirectional current flow.

Cevap

Terminal 1 is the anode, Terminal 2 is the cathode, and the diode is operational.
A properly functioning semiconductor diode conducts current when forward-biased (positive potential on the anode, negative potential on the cathode) and blocks current when reverse-biased (positive potential on the cathode, negative potential on the anode). Because the ohmmeter indicates low resistance when the positive lead connects to Terminal 1 and the negative lead connects to Terminal 2, Terminal 1 is the anode and Terminal 2 is the cathode. The infinite resistance displayed upon reversing the leads verifies that the PN junction is intact and the diode is operational.

Adım Adım Çözüm

1
Analyze the first meter reading for biasing conditions
Low resistance occurs when the positive lead is on Terminal 1 and the negative lead is on Terminal 2, which corresponds to forward bias.
A semiconductor diode only allows significant current to flow when its anode is made positive relative to its cathode.
2
Analyze the second meter reading for reverse-bias integrity
Infinite resistance when the leads are reversed corresponds to reverse bias.
A functioning PN junction establishes a depletion region that blocks current when the cathode is positive relative to the anode.
3
Identify terminal polarities and verify component health
Terminal 1 is the anode, Terminal 2 is the cathode, and the high front-to-back resistance ratio confirms normal diode operation.
A healthy diode exhibits low forward resistance and very high/infinite reverse resistance.

Anahtar Kavram

Diode terminal identification and continuity verification using front-to-back resistance measurements
Tahmini Süre:1m 0s
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