Regarding "Earthing" requirements as per Indian standards, consider the following:1.The earth neutral conductor shall be earthed at the source and at each point of supply.2.The resistance of the earth connection should be as high as possible for safety.3.Periodic testing of earth pits is a mandatory safety requirement.Which of the statements given above is/are correct?

Correct Answer: A - 1 and 3 only

Quick Concept Explanation

Protective earthing provides a low-impedance path for fault current and stabilizes exposed conductive parts/neutral references. Earth resistance should be low enough to meet protection requirements and is checked periodically because soil/moisture/corrosion can change electrode performance. Key relation: Touch voltage and disconnection time depend on earthing and protective-device coordination.

Exam focus: Low earth resistance is desirable—not high resistance. Common trap: Never state that high earth resistance improves safety.

Statement-wise Verification

• Statement 1 - Correct.
  The earth neutral conductor shall be earthed at the source and at each point of supply.
  Low earth resistance is desirable—not high resistance.
• Statement 2 - Incorrect.
  The resistance of the earth connection should be as high as possible for safety.
  Protective earthing seeks sufficiently low resistance/impedance so fault current can operate protection and touch voltage is limited
• Statement 3 - Correct.
  Periodic testing of earth pits is a mandatory safety requirement.
  Low earth resistance is desirable—not high resistance.

Core Concept

Protective earthing provides a low-impedance path for fault current and stabilizes exposed conductive parts/neutral references. Earth resistance should be low enough to meet protection requirements and is checked periodically because soil/moisture/corrosion can change electrode performance.

Formula / Key Relationship

Touch voltage and disconnection time depend on earthing and protective-device coordination.

Why the Other Options Are Wrong

Option B is incorrect because it includes incorrect statement(s) 2 and omits correct statement(s) 1. Option C is incorrect because it includes incorrect statement(s) 2 and omits correct statement(s) 3. Option D is incorrect because it includes incorrect statement(s) 2.

Exam Shortcut / Approach

Low earth resistance is desirable—not high resistance.

Common Mistake

Never state that high earth resistance improves safety.

Quick Revision

Neutral Earthing and Earth Resistance Testing is linked with Earthing Requirements, Earthing and Electrical Safety. Low earth resistance is desirable—not high resistance.