(a) A wire of resistance R, length l and area of cross-section A is cut into parts, having their lengths in the ratio 1:2. The shorter wire is now stretched till its length becomes equal to that of the longer wire. If they are now connected in parallel, find the net resistance of the combination.
(b) Write the name of the materials having resistivity of the order of (i) `1.7 xx 10^(-8) Omega m` and (ii) `10^(15) Omega m` at `0 ""^(@)C`.

Explanation

### Step-by-Step Solution

**(a)** Let's start by analyzing the wire and its properties.

1. **Cutting the Wire**:
- The wire is cut into two parts in the ratio 1:2.
- Let the length of the shorter wire be \( l_1 = \frac{l}{3} \) and the longer wire be \( l_2 = \frac{2l}{3} \).
- The resistance of a wire is given by the formula:
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