Question

Ohm’s law is true:
A. For metallic conductor at low temperature.
B. For metallic conductors at high temperatures.
C. For electrolytes, when current passes through them.
D. For diodes when current flows.

Answer 1

Hint:In order to answer this question, first we will choose the statement for the Ohm’s law and then we will discuss the reason behind the correct statement. And then we will also discuss Ohm's law.

Complete answer:
Ohm's law is true for metallic conductors at low temperatures."In metallic conductors at constant temperature and zero magnetic field, the current flowing is proportional to the voltage across the ends of the conductor, and is inversely proportional to the conductor's resistance," according to Ohm's Law.

Ohm's law states that "in metallic conductors" This means that the law applies to the majority of metals, but not all. Tungsten, for example, which is used in light bulb filaments, has a resistance that varies with the temperature of the filament, hence the reference to ‘at a constant temperature' in Ohm's Law.

There are some electronic components that have a non-linear relationship between the three electrical properties of voltage, current, and resistance, but these can be expressed using other equations. Ohm's Law can be used to explain the majority of circuits or components: Ohm’s law is represented numerically by:
$V = RI$
where, $V$ is the voltage across the resistance, $R$ is the resistance, and $I$ is the current.

Hence, the correct option is A.

Note:An ohmic substance or component is any material, component, or device that obeys Ohm's law, in which the current through the device is proportionate to the voltage supplied. A non ohmic substance or component is defined as one that does not obey Ohm's law.