Question

In Bainbridge mass spectrograph a potential difference of 1000 V is applied between two plates distant 1 cm apart and magnetic field in B = 1T. The velocity of undeflected positive ions in m/s from the velocity selector is

• A. ${10}^{5}m/s$
• B. ${10}^{4}m/s$
• C. ${10}^{3}m/s$
• D. ${10}^{2}m/s$

Answer 1

The correct option is A ${10}^{5}m/s$

By using $v=\frac{E}{B};whereE=\frac{V}{d}=\frac{1000}{1\times {10}^{-2}}={10}^{5}V/m\Rightarrow v=\frac{{10}^5}{1}={10}^{5}m/s.$