Rheostat with resistance 11 Ohm Made of nichrome wire with a cross-sectional area of 1.0 mm2.

Rheostat with resistance 11 Ohm Made of nichrome wire with a cross-sectional area of 1.0 mm2. Determine the length of the wire from which the rheostat is made.

R = 11 ohms.

S = 1mm ^ 2.

ρ = 1.1 Ohm * mm ^ 2 / m.

l -?

Since the rheostat is made of a cylindrical homogeneous nichrome wire, its resistance is expressed by the formula: R = ρ * l / S, where ρ is the resistivity of the material from which the wire is made, l is the length of the rheostat wire, S is the cross-sectional area of the wire.

The length of the wire will be determined by the formula: l = R * S / ρ.

We take the specific resistance of nichrome from the table of specific resistance of substances: ρ = 1.1 Ohm * mm ^ 2 / m.

l = 11 Ohm * 1 mm ^ 2 * / 1.1 Ohm * mm ^ 2 / m = 10 m.

Answer: the wire of the rheostat has a length of l = 10 m.