ExamBro
ExamBro
AP EAMCET · PHYSICS · Magnetic Effects of Current

Two toroids with number of turns 400 and 200 have arrange radii respectively 30 cm and 60 cm . If they carry the same current, the ratio of magnetic fields in these two toroids is

  1. A 2:1
  2. B 1:4
  3. C 2:3
  4. D 4:1
Verified Solution

Answer & Solution

Correct Answer

(D) 4:1

Step-by-step Solution

Detailed explanation

For toroid, magnetic field inside it is \(\begin{aligned} & B=\mu_0\left(\frac{N}{2 \pi R}\right) \cdot I \Rightarrow B \propto \frac{N}{R} \\ & \therefore \frac{B_1}{B_2}=\left(\frac{N_1}{N_2}\right)=\frac{400}{200} \times \frac{60}{30}=4: 1 \end{aligned}\)