A conducting rod PQ of length L = 1.0 m is moving with a uniform speed `v=2ms^(-1)` in a uniform magnetic field B = 4.0 T directed into the paper. A capacitor of capacity C = 10`muF` is connected as shown in figure. Then,

Options

A. (a) `q_(A) = + 80muC and q_(B) -80muC `
B. (b) `q_(A) = - 80muC and q_(B) + 80muC `
C. ( c) `q_(A) =0 = q_(B)`
D. (d) charge stored in the capacitor increases exponentially with time

Answer

A

Explanation

( a) `q = CV = C(Bvl)`
`=(10 xx 10^(-6))(4)(2)(1)`
`= 80muC = constant`
Magnetic force on the electron in the counducting rod `PQ` is towards `Q`. Therefore, `A` is positively charged and `B` is negatively charged.