Question

What is the full form of RL bottle?

Answer 1

The term "RL bottle" refers to a type of laboratory bottle used for various purposes, especially in chemistry and biology. "RL" stands for "Reusable Laboratory." These bottles are designed to be durable and can be reused multiple times, which makes them ideal for laboratory settings where repeated use of glassware is common.

RL bottles typically have a high-quality glass construction, which helps in maintaining the integrity of the contents and ensures resistance to chemicals and temperature changes. They come in various sizes and types, including narrow and wide mouth options, depending on the specific needs of the experiment or procedure. Their design often includes features such as standardized neck sizes for compatibility with other laboratory equipment and closures that prevent contamination or spillage.

In summary, "RL" in "RL bottle" highlights the bottle's suitability for repeated use in laboratory environments.

Answer 2

When a wire is stretched to four times its initial length, its resistance changes. To determine the new resistance, we need to understand how stretching affects the wire's physical properties.

Here’s the step-by-step process:

1. **Initial Parameters**:
   - Original length of the wire: \( L \)
   - Original resistance of the wire: \( R \)
   - Original cross-sectional area of the wire: \( A \)
   - Resistivity of the material: \( \rho \)

2. **Resistance Formula**:
   The resistance \( R \) of a wire is given by:
   \[
   R = \frac{\rho L}{A}
   \]

3. **Effects of Stretching**:
   - **Length**: If the wire is stretched to four times its original length, the new length \( L' \) is:
     \[
     L' = 4L
     \]
   - **Volume Conservation**: When a wire is stretched, its volume remains constant (assuming it doesn't break or change phase). The volume before and after stretching is:
     \[
     V = A \times L = A' \times L'
     \]
     where \( A' \) is the new cross-sectional area after stretching.

   Rearranging to find the new cross-sectional area:
   \[
   A' = \frac{A \times L}{L'} = \frac{A \times L}{4L} = \frac{A}{4}
   \]

4. **New Resistance Calculation**:
   With the new length \( L' \) and new cross-sectional area \( A' \), the new resistance \( R' \) is:
   \[
   R' = \frac{\rho L'}{A'}
   \]
   Substituting \( L' = 4L \) and \( A' = \frac{A}{4} \):
   \[
   R' = \frac{\rho \times 4L}{\frac{A}{4}} = \frac{4 \rho L}{\frac{A}{4}} = \frac{4 \rho L \times 4}{A} = 16 \frac{\rho L}{A}
   \]
   So:
   \[
   R' = 16R
   \]

**Conclusion**: When the wire is stretched to four times its original length, its resistance increases to 16 times its original resistance.