what will happen to e/m ratio of cathode rays when voltage is double?
Answers
Answer:
In this experiment you will measure e/m, the ratio of the charge of an electron to the mass of an electron. The currently accepted value for e/m is 1.758820 × 1011 C/kg.
When an electron enters a region in which there is a uniform magnetic field, B, perpendicular to the velocity, v, of the electron (Caution: The capital letter V will be used below to represent voltage. Don't confuse v with V!), the electron experiences a force, F, with a magnitude given by the following equation.
( 1 )
F = evB
The force is perpendicular to both v and B and its direction can be found by using the right-hand rule. The force will cause the electron to move in a circular orbit with radius r (uniform circular motion). Equating this force to the mass times the centripetal acceleration,