Final answer:
An active sensor generates its own voltage signal, and this statement is true. Active sensors use their own energy to create a signal, distinguishing them from passive sensors that rely on external energy sources. Option 1 is correct.
Step-by-step explanation:
An active sensor is one that generates its own voltage signal. This statement is true. Active sensors have their own source of energy to produce a signal. For example, radar systems send out radio waves and measure the energy reflected back.
Regarding the additional true/false statements provided:
A current is created in a photoconductive cell even if only one electron is expelled from a photon strike. This statement is true. The displacement of even a single electron due to photon impact can induce a small current.
Visible light is the only type of electromagnetic radiation that can cause the photoelectric effect. This statement is false. Ultraviolet light and other types of electromagnetic radiation above a certain frequency can also cause the photoelectric effect.
If you drop a bar magnet through a copper tube, it induces an electric current in the tube. This statement is true. The changing magnetic flux as the magnet falls through the tube induces current by Faraday's law of electromagnetic induction.
In a circuit diagram, we can assume that the voltage is the same at every point in a given wire. This statement is false if the wire has resistance or is part of a complex circuit where potential differences can occur due to other elements in the circuit.
A pebble dropped in water is an example of a pulse wave. This statement is true. The ripple effect created by dropping a pebble in water is indeed a pulse wave, as it is a single disturbance that travels through a medium.
Charging an object by polarization requires touching it with an object carrying excess charge. This statement is false. Polarization can occur without direct contact when an electric field reorients the charges within a material, causing one side to become more positively charged and the other more negatively charged.
As for sensory transduction, it's a process by which all types of senses undergo by converting a stimulus into an electrical signal via the peripheral nervous system, contributing to the sensation and perception.
Quorum sensing relates to the regulation of gene expression in response to fluctuations in cell-population density. The statement that autoinducers must bind to receptors to turn on transcription of genes is true, as this is a central mechanism of quorum sensing.