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Which of the following will NOT be observed when a multimeter (operating in resistance measuring mode) probes connected across a component, are just reversed? (1) Multimeter shows an equal deflection in both cases i.e. before and after reversing the probes if the chosen component is resistor. (2) Multimeter shows NO deflection in both cases i.e. before and after reversing the probes if the chosen component is metal wire. (3) Multimeter shows a deflection, accompanied by a splash of light out of connected component in one direction and NO deflection on reversing the probes if the chosen component is LED. (4) Multimeter shows NO deflection in both cases i.e. before and after reversing the probes if the chosen component is capacitor.

1. Multimeter shows an equal deflection in both cases i.e. before and after reversing the probes if the chosen component is resistor.
2. Multimeter shows NO deflection in both cases i.e. before and after reversing the probes if the chosen component is metal wire.
3. Multimeter shows a deflection, accompanied by a splash of light out of connected component in one direction and NO deflection on reversing the probes if the chosen component is LED.
4. Multimeter shows NO deflection in both cases i.e. before and after reversing the probes if the chosen component is capacitor.

Correct answer: Multimeter shows a deflection, accompanied by a splash of light out of connected component in one direction and NO deflection on reversing the probes if the chosen component is LED.

Solution

The LED is a diode that allows current to flow in only one direction, which is why it shows a deflection and emits light when the probes are correctly oriented, but shows no deflection when reversed, demonstrating its unidirectional conductivity.

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