If a charged particle of charge `5muC` and mass 5 g is moving with constant speed 5 m"/"s in a uniform magnetic field B on a curve `x^(2) + y^(2) = 25`, where x and y are in metre. The value of magnetic field will be

Options

A. 1KT along x-axis
B. 1KT along z-axis
C. 5KTalong the x-axis
D. 1KTalong any line in the x-y plane

Answer

B

Explanation

`x^(2)+y^(2)=25:.r=5m`
`:.r=(mv)/(qB) or5=(5xx10^(-3)xx5)/(5xx10^(-6)xxB)`
`orB=(5xx10^(-3)xx5)/(5xx10^(-6)xx 5)=10^(-3)T=1KT`
The magnetic field will be 1 kT along z-axis.