Question

The magnetic field at the centre of a 50cm long solenoid is 4.0 × 10–2 NA–1 m–1 when a current of 8.0A flows through it, calculate the number of turns in the solenoid

Answer 1

Answer ⇒ The no. of turns is 2000.

Explanation ⇒ Given conditions,

Length = 50 cm.

B = 4.0 × 10⁻² T

Current(i) = 8 A

Using the formula,

B = μ₀N/l × i

∴ 4.0 × 10⁻² = 4π × 10⁻⁷ × N/0.5 × 8

10⁵ × 0.5/8π = N

∴ N = 0.0198 × 10⁵

∴ N = 1.98 × 10³

OR, N ≈ 2000 Turns.

Hope it helps.

Answer 2

Answer:

Length = 50 cm.

B = 4.0 × 10⁻² T

Current(i) = 8 A

Using the formula,

B = μ₀N/l × i

∴ 4.0 × 10⁻² = 4π × 10⁻⁷ × N/0.5 × 8

10⁵ × 0.5/8π = N

∴ N = 0.0198 × 10⁵

∴ N = 1.98 × 10³

Explanation: