Length of the aluminium is 1 km. \

The diameter of the aluminum wire is d1= 3 mm.

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Since the length are same, the length of the copper wire is 1 km.

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Specific resistivity of the aluminum is \"\".

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Specific resistivity of the copper \"\".

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Total current in the circuit is it = 350 A.

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Current through copper wire is i2 = 150 A.

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The aluminum wire and copper wire are connected in parallel.

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Total Current = i1 + i2 .

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350 = i1 + 150

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i1  =350 - 150

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i1 = 200 A.

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Current through aluminum wire is  i1 = 200 A.

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Step 2:

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Law of Resistivity:

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Resistance offered by a conductor is given by \"\".

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Resistance offered by aluminum wire is \"\".

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Area of the aluminum wire is \"\".

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Resistance offered by aluminum wire is \"\".

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Resistance offered by copper wire is \"\".

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Area of the copper wire is \"\".

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Resistance offered by copper wire is \"\".

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Ratio of the resistance is

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\"\"

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Step 3:

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In a parallel combination, the voltage across the element are same.

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\"\"

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\"\"

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Substitute \"\"in equation (1).

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\"\"

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Substitute the corresponding values in the above formula.

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\"\"

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The diameter of the copper wire is 2.862 mm.

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Step 1:

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(1.3.2)

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Specific resistivity of the aluminum \"\".

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Specific resistivity of the copper \"\".

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Voltage drop across the aluminum is \"\".

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Current through copper wire is i2 = 150 A.

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Current through aluminum wire is  i1 = 200 A.

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The diameter of the aluminum wire is d1 = 3 mm.

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The diameter of the copper wire is d2 = 2.862 mm.

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Resistance offered by aluminum wire is \"\".

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\"\"

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Resistance offered by aluminum is \"\".

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Voltage drop across the aluminum:

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\"\"

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Voltage drop across the aluminum is 792.2 v.

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In a parallel combination, the voltage across both the elements are same.

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Voltage drop across the copper is also 792.2 v.

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Solution:

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Voltage drop across the conductors is 792.2 v. 

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Step 1:

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A coil has a resistance 300 ohms at \"\"C.

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Here, \"\" ohms and \"\"C.

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Temperature coefficient of the resistance \"\"C .

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Thus, \"\"C.

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Find the resistance increase of the coil, if the motor reaches \"\"C.

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\"\"C.

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\"\"

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\"\"

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Substitute corresponding values in the above expression.

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\"\"

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\"\"

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Su

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\"\"

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Therefore the temperature coefficient is 0.004 per

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