Question

The magnetic field intensity due to a solenoid at end point $P$ is :

• A. ${\mu }_{0}nI$
• B. $\frac{{\mu }_{0}nI}{2}$
• C. $\frac{{\mu }_{0}nI}{2}(\cos \theta -\cos \varphi )$
• D. $\frac{{\mu }_{0}nI}{2}(\sin \theta -\sin \varphi )$

Answer 1

The correct option is B $\frac{{\mu }_{0}nI}{2}$

Magnetic field due to solenoid =$\frac{{\mu }_{0}ni(\cos \theta -\cos \varphi )}{2}$
$|B|$ due to solenoid at P =$\frac{{\mu }_{0}ni(\cos 0^o-\cos {90}^o)}{2}=\frac{{\mu }_{0}ni}{2}$