AP EAMCET20225 Jul 2022Morning ShiftPhysicsMagnetic Effects of CurrentActual
An electron having kinetic energy of 100 eV circulates in a path of radius 10 ~cm in a magnetic field. The magnitude of magnetic field | B | is approximately [Mass of electron =0.5 MeV c ⁻² , where c is the velocity of light].
Options
- A3.3 10⁻⁴ ~T
- B2.6 10⁻⁴ ~T
- C1.70 10⁻⁴ ~T
- D4.3 10⁻⁴ ~T
Correct answer
A. 3.3 10⁻⁴ ~T
Step-by-step solution
Kinetic energy of electron, aligned K & =100 eV & =100 1.5 10⁻¹⁹ ~J =1.6 10⁻¹⁷ ~J aligned Radius of circular path, r=10 ~cm =0.1 ~m Mass of electron, m=0.5 MeVc ⁻²= 0.5 MeV c^2 = 0.5 10^6 1.6 10⁻¹⁹ 3 10^8 3 10^8 ~kg =8.89 10⁻³¹ ~kg Radius of circular path of electron in magnetic field B in terms of kinetic energy (K) is given as r= 2 m K B q B= 2 m K r q = 2 8.89 10⁻³¹ 1.6 10⁻¹⁷ 0.1 1.6 10⁻¹⁹ =3.3 10⁻⁴ ~T