Final answer:
The questions address several physical phenomena: electromagnetic induction (true), the nature of high-voltage transmission lines (false), the behavior of electric-field lines (true), the impact of conduit radius on flow rate (significantly affected), and the application of refraction in fiber optic technology (true).
Step-by-step explanation:
The subject of the question being addressed is Physics, more specifically, it is related to electromagnetic phenomena, the behavior of electric fields, the principles of fluid dynamics, and the concept of refraction as applied in physics. The questions touch upon the interactions between magnets and conductive materials, the properties of high-voltage transmission lines, the nature of electric fields from point charges, the effects of changing physical dimensions on fluid flow, and the optical principle of refraction in fiber optics.
Electromagnetic Induction
If you drop a bar magnet through a copper tube, it induces an electric current in the tube. This statement is true because of electromagnetic induction. When a magnet moves through a conductor, it creates a changing magnetic field, which in turn induces an electric current.
Electric Transmission
The high-voltage wires seen connected to tall metal-frame towers are indeed held aloft by insulating connectors; however, these wires typically are not wrapped in insulation material due to their high placement and the impracticality of insulating such high-voltage lines. This statement is false.
Electric Fields
The electric-field lines from a positive point charge do indeed spread out radially and point outward from the charge. This description accurately represents the behavior of electric fields emanating from a positive point charge, making the statement true.
Fluid Dynamics
Cutting the radius of a conduit in half decreases the flow rate to one-sixteenth the original flow rate, a rule derived from the principles of fluid dynamics assuming laminar flow. This dramatic change illustrates the significant effect that the radius of a conduit has on the flow rate of a fluid.
Optics
Refraction is the bending of light as it passes from one medium into another at an angle other than 90 degrees. This principle is indeed useful in fiber optic cables, where light signals are transmitted with minimal loss over long distances. This makes the statement concerning refraction's utility in fiber optics true.