The magnetic flux density at a point on the axis of a long solenoid having 1000 turns/m when it is carrying a current of 3.4 A is nearly,
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → $4.4 \times 10^{-3} T$
The magnetic flux density $(\vec B)$ at a point on the axis of a long solenoid is given by the -
$B=μ_0nI$
where,
$μ_0$ = Permeability of space = $4π×10^{-7}$
$n$ = Number of turns
$I$ = Current through solenoid
$B=(4π×10^{-7})×1000×3.4$
$≃4.4 \times 10^{-3} T$