Three resistors, 21 ω, 58 ω, and 64 ω, are connected in series, and a 0.50-a current passes through them. what are (a) the equivalent resistance and (b) the potential difference across this equivalent resistance?

Explanation:

When resistors are connected in series, effective resistance is given by

Here

         R₁ = 21Ω

         R₂ = 58Ω

         R₃ = 64Ω

a)      

  Equivalent resistance is 143 Ω

b) We know

               Potential difference = Current x Resistance

               V = IR

               I = 0.5 A

               R = 143Ω

Substituting

               V = 0.5 x 143 = 71.5 V

Potential difference is 71.5 V

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.

the answer is a. hope this .