NEET2025PhysicsMagnetic Effects of CurrentActual
An electron (mass 9 10⁻³¹ ~kg and charge 1.6 10⁻¹⁹ C ) moving with speed c / 100( c = speed of light) is injected into a magnetic field B of magnitude 9 10⁻⁴ ~T perpendicular to its direction of motion. We wish to apply an uniform electric field E together with the magnetic field so that the electron does not deflect from its path. Then (speed of light c =3 10^8 ~ms ⁻¹ )
Options
- AE is perpendicular to B and its magnitude is 27 10^4 ~V ~m ⁻¹
- BE is perpendicular to B and its magnitude is 27 10^2 Vm ⁻¹
- CE is parallel to B and its magnitude is 27 10^2 ~V ~m ⁻¹
- DE is parallel to B and its magnitude is 27 10^4 ~V ~m ⁻¹
Correct answer
B. E is perpendicular to B and its magnitude is 27 10^2 Vm ⁻¹
Step-by-step solution
For particle To Remain undeflected aligned & F _e=- F _ m & | E |= VB & E = c 100 9 10⁻⁴ 90 & E =27 10^2 ~V / m and & E = B V aligned