Final answer:
The observed frequency does not become infinite when the source is moving at the sound's speed, thus the statement is false. Literal constants such as the speed of light have fixed values in scientific equations. The term hypothesis is most closely related to 'suggestion', and voltage in a circuit is not assumed to be the same at every point in a given wire, making that statement false.
Step-by-step explanation:
The statement 'The observed frequency becomes infinite when the source is moving at the speed of sound' is false. When the source of sound moves at the speed of sound, the frequency observed does not become infinite; rather, all the waves pile up at one point leading to the formation of a shock wave. This is known as the sonic boom. Infinitesimally increased frequency happens only theoretically if the source could move faster than the speed of sound, which would be a supersonic speed and is not implied by the statement.
A literal constant is a value that does not change within a given context or expression. In mathematics and science, constants like the speed of light, Planck's constant, and Avogadro's number have specific values that do not change. These are different from variables, which can change depending on the situation.
The term hypothesis is closest in meaning to suggestion (d). A hypothesis is a proposed explanation for a phenomenon, which is then tested through experimentation and observation. It is not a proven fact or law but rather a starting point for scientific inquiry.
Regarding the truth of statements, a true statement accurately describes reality. For example, 'Dogs are mammals' is true because dogs indeed belong to the class Mammalia. This relates to Aristotle's idea that a statement is true if it asserts of something that it is what it is.
In the context of electrical circuits, the statement 'In a circuit diagram, we can assume that the voltage is same at every point in a given wire' is false. Voltage can vary across different points in a circuit due to the presence of components like resistors that cause a voltage drop along the circuit.