A Conduckor has an inikiah Length L1 and cross Seetionah area, A. Ik is drawn uniformly to a final length L2 =10L1 and anealed. If the conduetor at the new Length is F5se, us hat is the initial value of R

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### Problem Statement

A conductor has an initial length \( L_1 \) and cross-sectional area \( A \). It is drawn uniformly to a final length \( L_2 = 10L_1 \) and annealed. If the resistance of the conductor at the new length is 75Ω, what is the initial value of \( R \)?

### Explanation

This problem involves understanding the relationship between the length, cross-sectional area, and resistance of a conductor. When the conductor is uniformly drawn out to a longer length, its cross-sectional area decreases. The change in these dimensions affects the electrical resistance of the conductor.

Given:
- Initial length of the conductor: \( L_1 \)
- Final length of the conductor: \( L_2 = 10L_1 \)
- Final resistance of the conductor: 75Ω

To find:
- Initial resistance of the conductor: \( R \)

### Key Concepts

1. **Resistance of a Conductor**:
   The resistance \( R \) of a conductor is given by the formula:
   \[
   R = \rho \frac{L}{A}
   \]
   where \( \rho \) is the resistivity of the material, \( L \) is the length, and \( A \) is the cross-sectional area.

2. **Effect of Drawing on Dimensions**:
   When the conductor is drawn out to a new length, its volume remains constant. Therefore:
   \[
   L_1 \cdot A_1 = L_2 \cdot A_2
   \]
   Simplifying, since \( L_2 = 10L_1 \):
   \[
   A_2 = \frac{A_1}{10}
   \]

3. **New Resistance**:
   With the new length and cross-sectional area, the new resistance \( R_2 \) can be written as:
   \[
   R_2 = \rho \frac{L_2}{A_2} = \rho \frac{10L_1}{A_1 / 10} = 100 \rho \frac{L_1}{A_1}
   \]

   Given \( R_2 = 75Ω \), we can solve for the initial resistance \( R_1 \):
   \[
   R_2 = 100R_1 \Rightarrow 75Ω = 100R_1
Transcribed Image Text:### Problem Statement A conductor has an initial length \( L_1 \) and cross-sectional area \( A \). It is drawn uniformly to a final length \( L_2 = 10L_1 \) and annealed. If the resistance of the conductor at the new length is 75Ω, what is the initial value of \( R \)? ### Explanation This problem involves understanding the relationship between the length, cross-sectional area, and resistance of a conductor. When the conductor is uniformly drawn out to a longer length, its cross-sectional area decreases. The change in these dimensions affects the electrical resistance of the conductor. Given: - Initial length of the conductor: \( L_1 \) - Final length of the conductor: \( L_2 = 10L_1 \) - Final resistance of the conductor: 75Ω To find: - Initial resistance of the conductor: \( R \) ### Key Concepts 1. **Resistance of a Conductor**: The resistance \( R \) of a conductor is given by the formula: \[ R = \rho \frac{L}{A} \] where \( \rho \) is the resistivity of the material, \( L \) is the length, and \( A \) is the cross-sectional area. 2. **Effect of Drawing on Dimensions**: When the conductor is drawn out to a new length, its volume remains constant. Therefore: \[ L_1 \cdot A_1 = L_2 \cdot A_2 \] Simplifying, since \( L_2 = 10L_1 \): \[ A_2 = \frac{A_1}{10} \] 3. **New Resistance**: With the new length and cross-sectional area, the new resistance \( R_2 \) can be written as: \[ R_2 = \rho \frac{L_2}{A_2} = \rho \frac{10L_1}{A_1 / 10} = 100 \rho \frac{L_1}{A_1} \] Given \( R_2 = 75Ω \), we can solve for the initial resistance \( R_1 \): \[ R_2 = 100R_1 \Rightarrow 75Ω = 100R_1
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