An electron moving with a speed u along the positive x-axis at y = 0 enters a region of uniform magnetic field B=-B0 k which exists to the right of v-axis. The electron exits from the region after sometime with the speed v at coordinate y, then

Question

An electron moving with a speed u along the positive x-axis at y = 0 enters a region of uniform magnetic field B=-B0 k which exists to the right of v-axis. The electron exits from the region after sometime with the speed v at coordinate y, then (A) v > u, y < 0 (B) v = u, y > 0 (C) v > u, y > 0 (D) v = u, y < 0

Tardigrade Admin · Accepted Answer

Magnetic force does not change the speed of charged particle.
Hence, v = u. Further magnetic field on the electron in the given condition is along negative y-axis in the starting. Or it describes a circular path in clockwise direction. Hence, when it exits from the field, y < 0

Q. An electron moving with a speed u along the positive x-axis at y=0 enters a region of uniform magnetic field B=−B0​k which exists to the right of v-axis. The electron exits from the region after sometime with the speed v at coordinate y, then

v > u, y < 0

v = u, y > 0

v > u, y > 0

v = u, y < 0

Magnetic force does not change the speed of charged particle. Hence, v = u. Further magnetic field on the electron in the given condition is along negative y-axis in the starting. Or it describes a circular path in clockwise direction. Hence, when it exits from the field, y < 0

Q. An electron moving with a speed $u$ along the positive x-axis at $y = 0$ enters a region of uniform magnetic field $B = - B_{0} k$ which exists to the right of $v$ -axis. The electron exits from the region after sometime with the speed $v$ at coordinate $y$ , then

Magnetic force does not change the speed of charged particle.
Hence, v = u. Further magnetic field on the electron in the given condition is along negative y-axis in the starting. Or it describes a circular path in clockwise direction. Hence, when it exits from the field, y < 0