A sinking output NPN sensor energizes and its output voltage is what?

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Multiple Choice

A sinking output NPN sensor energizes and its output voltage is what?

In a sinking output NPN sensor, the transistor pulls the output toward ground when it energizes, acting as a low-side switch. When the sensor is on, current flows from the supply through the load into the transistor to ground, so the output node is driven to near 0 volts. In reality, it’s the small saturation voltage of the transistor (a few hundred millivolts) above ground, but effectively it is ground potential. That’s why the output voltage is zero when energized. If it weren’t energized, the output would be pulled up toward Vcc by the load or a pull-up resistor, not toward zero. The other options don’t fit typical sinking-output behavior.

In a sinking output NPN sensor, the transistor pulls the output toward ground when it energizes, acting as a low-side switch. When the sensor is on, current flows from the supply through the load into the transistor to ground, so the output node is driven to near 0 volts. In reality, it’s the small saturation voltage of the transistor (a few hundred millivolts) above ground, but effectively it is ground potential. That’s why the output voltage is zero when energized.

If it weren’t energized, the output would be pulled up toward Vcc by the load or a pull-up resistor, not toward zero. The other options don’t fit typical sinking-output behavior.

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