Determine the magnitude and direction of the force between two parallel wires 35 m long and 3.0 cm apart, each carrying 35 a in the same direction.

Answer;

= 0.2858 N, attractive

Explanation;

Since the currents are parallel, the force on each wire will be attractive, toward the other wire. Therefore; to calculate the magnitude of force we use the formula;

F2 = (μ₀/2π)(I₁I₂/d)I₂

Where;

μ₀ = constant = 4π × 10^-7 H/m,

I₁, I₂ are the currents,

L s the length o the wire,

d is the distance between these two wires

if current are in same direction, they exert attractive force on each other and if currents are in opposite direction, they exert repulsive force

Therefore;

   F₂ = (4π × 10^-7 T.m/A)/2π) × ((35 A)²/ 0.03 m)× 35 m

    = 0.2858 N, attractive

26.4 is about the right time

If the heat engine is a perfect carnot cycle engine, thenefficiency = (t2-t1)/t2   where t1=temperature of cold reservoir ( ° k) = 135            t2=temperature of hot reservoir ( ° k)   = 325thereforeefficiency = (t2-t1)/t2 = (325-135)/325 = 0.5846 = 58%  note: this is the theoretical maximum efficiency of a perfect heat engine.   real-life engines do not achieve this value.