A : High voltage ( high tension ) supply must have very large internal resistance.
R: If the circuit is accidentally shorted , then the current drawn will not exceed safely limits if internal resistance is high.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion , then mark
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion then mark.
C. If Assertion is ture statement but Reason is false , then mark
D. If both Assertion and Reason are false statements then mark.

Answer

To solve the assertion and reason question, we will analyze both statements step by step.

### Step 1: Understanding the Assertion
**Assertion (A):** High voltage (high tension) supply must have very large internal resistance.

- High voltage supplies are used to transmit power over long distances. The reason for having a high internal resistance is to limit the current that can flow in the event of a short circuit. This is crucial for safety purposes.

### Step 2: Analyzing the Circuit
- Let’s denote the electromotive force (EMF) of the supply as \( E \), the internal resistance of the supply as \( r \), and the load resistance as \( R \).
- The total resistance in the circuit when connected is \( R + r \).
- The current \( I \) flowing through the circuit can be calculated using Ohm's Law:
\[ I = \frac{E}{R + r} \]

### Step 3: Implications of High Internal Resistance
- If the internal resistance \( r \) is very large, the overall current \( I \) will be limited even if the voltage \( E \) is high.
- This means that in normal operation, the current remains low, which is essential for safety, especially in household circuits.

### Step 4: Understanding the Reason
**Reason (R):** If the circuit is accidentally shorted, then the current drawn will not exceed safe limits if internal resistance is high.

- In the event of a short circuit (where \( R \) approaches zero), the current would theoretically be:
\[ I = \frac{E}{r} \]
- If \( r \) is very large, even with a high \( E \), the resulting current \( I \) will still be within safe limits. This is because a high internal resistance limits the amount of current that can flow, protecting both the circuit and individuals from dangerous levels of current.

### Step 5: Conclusion
- Both the assertion and the reason are correct.
- The reason provided is a correct explanation of the assertion, as it highlights the safety aspect of having high internal resistance in high voltage supplies.

### Final Answer
Both Assertion (A) and Reason (R) are correct, and R is the correct explanation of A.

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