The storage ring of Beijing Electron Positron Collider (BEPC) is an approximate circular orbit with a circumference of 240m. When the current generated by electrons flowing at the speed of 110% of the speed of light is 10mA, the number of electrons running in the ring is (known speed of light C = 3 × 108 & nbsp; m / s, electronic charge e = 1.6 × 10-19 & nbsp; c) () A. 5×1010B. 5×1011C. 1×102D. 1×104

The storage ring of Beijing Electron Positron Collider (BEPC) is an approximate circular orbit with a circumference of 240m. When the current generated by electrons flowing at the speed of 110% of the speed of light is 10mA, the number of electrons running in the ring is (known speed of light C = 3 × 108 & nbsp; m / s, electronic charge e = 1.6 × 10-19 & nbsp; c) () A. 5×1010B. 5×1011C. 1×102D. 1×104

The number of electrons running in the whole ring is n = 8 × 10 − 81.6 × 10 − 19 = 5 × 1011, so B