Question

A thin semicircular conducting ring (PQR) of radius r is falling with its plane vertical in a horizontal magnetic field B, as shown in figure. The potential difference developed across the ring when its speed is v, is ____________.

Options

• zero

• Bvπr²/2 and P is at higher potentia

• πrBv and R is at higher potential

• 2rBv and R is at higher potential

Answer 1

A thin semicircular conducting ring (PQR) of radius r is falling with its plane vertical in a horizontal magnetic field B, as shown in figure. The potential difference developed across the ring when its speed is v, is 2rBv and R is at higher potential.

Explanation:

`"e" = "B"l_"eff" "v" ("where"  l_"eff" ="Diameter")`

`= "B" (2"r")"v" = 2"rBv"`

and R is at higher potential by Fleming's right hand rule.