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A wire of resistance 2.20 Omega has a le...

A wire of resistance `2.20 Omega` has a length `2m`. Calculate the length of the similar wire which connected in parallel with `2m` length wire will give a resistance of `2.0 Omega`

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To solve the problem, we need to find the length of a similar wire that, when connected in parallel with a 2-meter wire of resistance 2.20 Ω, results in a total resistance of 2.0 Ω. ### Step-by-Step Solution: 1. **Identify Given Values**: - Resistance of the first wire (R1) = 2.20 Ω - Length of the first wire (L1) = 2 m - Desired total resistance (R_total) = 2.0 Ω 2. **Calculate the Resistance per Unit Length**: The resistance per unit length (R_per_unit_length) can be calculated using the formula: \[ R_{\text{per unit length}} = \frac{R_1}{L_1} \] Substituting the known values: \[ R_{\text{per unit length}} = \frac{2.20 \, \Omega}{2 \, \text{m}} = 1.1 \, \Omega/\text{m} \] 3. **Use the Formula for Parallel Resistance**: When two resistors (R1 and R2) are in parallel, the total resistance (R_total) can be calculated using the formula: \[ \frac{1}{R_{\text{total}}} = \frac{1}{R_1} + \frac{1}{R_2} \] Here, R2 is the resistance of the second wire, which we need to find. 4. **Express R2 in Terms of Length**: The resistance of the second wire (R2) can be expressed in terms of its length (L2): \[ R_2 = R_{\text{per unit length}} \times L_2 = 1.1 \, \Omega/\text{m} \times L_2 \] 5. **Substitute R1 and R2 into the Parallel Resistance Formula**: Substitute R1 and R2 into the parallel resistance formula: \[ \frac{1}{2.0} = \frac{1}{2.20} + \frac{1}{1.1 \times L_2} \] 6. **Solve for L2**: Rearranging the equation gives: \[ \frac{1}{1.1 \times L_2} = \frac{1}{2.0} - \frac{1}{2.20} \] Finding a common denominator for the right-hand side: \[ \frac{1}{2.0} = \frac{11}{22}, \quad \frac{1}{2.20} = \frac{10}{22} \] So, \[ \frac{1}{1.1 \times L_2} = \frac{11 - 10}{22} = \frac{1}{22} \] Therefore, \[ 1.1 \times L_2 = 22 \quad \Rightarrow \quad L_2 = \frac{22}{1.1} = 20 \, \text{m} \] ### Final Answer: The length of the similar wire (L2) that needs to be connected in parallel is **20 meters**. ---

To solve the problem, we need to find the length of a similar wire that, when connected in parallel with a 2-meter wire of resistance 2.20 Ω, results in a total resistance of 2.0 Ω. ### Step-by-Step Solution: 1. **Identify Given Values**: - Resistance of the first wire (R1) = 2.20 Ω - Length of the first wire (L1) = 2 m - Desired total resistance (R_total) = 2.0 Ω ...
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A uniform wire which connected in parallel with the 2 m long wire, will give a resistance of 2.0 Omega .

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Knowledge Check

  • What is the length of the wire if the specific resistance of a wire is rho , volume is 3 m^(3) and its resistance is 3 Omega .

    A
    `sqrt(1//rho)`
    B
    `3//sqrt(rho)`
    C
    `sqrt(3)//rho`
    D
    `rho//sqrt(3)`
  • A 10 m long wire of uniform cross section and 20 Omega resistance is used in a potentiometer. The wire is connected in series with a battery of 5 V along with an external resistance of 480 Omega . If an unknown emf E is balanced at 6.0 m length of the wire, then the value of unknown emf is:

    A
    `1.2V`
    B
    `1.02V`
    C
    `0.2V`
    D
    `0.12V`
  • A wire of length 3 m connected in the left gap of a metre bridge balances a 8 Omega resistance in the right gap at a point, which divides the bridge wire in the ratio of 3 :2 . What is the length of the wire corresponding to a resistance of the length of the wire corresponding to a resistance of 1 Omega ?

    A
    1m
    B
    0.75 m
    C
    0.5 m
    D
    0.25 m
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