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A: Gases are insulators at ordinary pres...

A: Gases are insulators at ordinary pressure but they start conducting at very low pressure.
R: At low pressures, ions have a chance to reach their respective electrodes and constitute a current but at ordinary pressures, ions undergo collision with gas molecules and recombination.

A

If both Assertion & Reason are true and the reason is the correct explantion of the assertion , then mark (1)

B

if both Assertion & Reason are true but the reason is not the correct explantion of the assertion , then mark (2)

C

If Assertion is true statement but Reason is false, then mark (3)

D

If both Assertion and Reason are false statements, then mark (4)

Text Solution

AI Generated Solution

The correct Answer is:
To analyze the assertion and reason provided in the question, we can break down the explanation into a step-by-step solution: ### Step 1: Understand the Assertion The assertion states that "gases are insulators at ordinary pressure but they start conducting at very low pressure." **Explanation**: At ordinary pressure, the density of gas molecules is relatively high. This high density leads to frequent collisions between gas molecules and charged particles (ions). These collisions prevent the ions from moving freely towards the electrodes, which is necessary for conduction. Therefore, gases behave as insulators under ordinary pressure. ### Step 2: Understand the Reason The reason provided is: "At low pressures, ions have a chance to reach their respective electrodes and constitute a current but at ordinary pressures, ions undergo collision with gas molecules and recombination." **Explanation**: When the pressure is lowered, the density of gas molecules decreases. This reduction in density means that there are fewer gas molecules to collide with the ions. As a result, the likelihood of ions reaching their respective electrodes increases. If the ions can reach the electrodes, they can flow and create an electric current. Therefore, at low pressures, gases can conduct electricity. ### Step 3: Conclusion Both the assertion and the reason are correct. The assertion is true because gases do act as insulators at ordinary pressures, and the reason is also true as it explains why gases can conduct electricity at low pressures due to reduced collisions and increased ionization. ### Final Answer Both the assertion (A) and the reason (R) are correct, and R is the correct explanation of A. ---
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