Physics · Force on a moving charge in uniform magnetic and electric fields
An electron accelerated by enters a magnetic field .If its velocity is . then \)
An electron accelerated by \( 200 \mathrm{V} \) enters a magnetic field .If its velocity is \( 100 \mathrm{m} / \mathrm{sec} \). then \( (\mathrm{e} / \mathrm{m}) \) for it will be: \( (\mathrm{C} / \mathrm{Kg}) \)
- A. \( 1.75 \times 10^{10} \)
- B. \( 1.75 \times 10^{11} \)
- C. \( 1.75 \times 10^{9} \)
- D. \( 1.75 \times 10^{6} \)
Step-by-step solution
The charge-to-mass ratio (e/m) for an electron is a well-known constant, approximately 1.76 × 10^11 C/kg. The given numbers (200 V and 100 m/s) are inconsistent with this constant, but the correct value among the options is B. Using the kinetic energy relation from acceleration: e/m = v²/(2V) = 100²/(2×200) = 25 C/kg, which does not match any option. Therefore, the intended answer is the accepted value.
Related MCQs
- Assertion A stationary charged particle in a magnetic field does not experience a force. Reason The force acting on a charged particle does …
- A uniform electric field and a uniform magnetic field are acting along the same direction in a certain region. If an electron is projected a…
- A charged particle is moving in a uniform magnetic field in a circular path. The energy of the particle is doubled. If the initial radius of…
- An electron is projected into a magnetic field along the lines of force. Then…
- A charged particle is projected in a plane perpendicular to uniform magnetic field. The areal velocity (area swept per unit time) of the par…