The specific charge (e/m) of the electron, determined by J. J. Thomson…

Question

The specific charge (e/m) of the electron, determined by J. J. Thomson, is approximately

Accepted Answer

A. {'text': '1.76 × 10¹¹ C/kg', 'label': 'A'}

1. J. J. Thomson used crossed E and B fields to measure e/m of cathode-ray particles.
2. The accepted value is e/m ≈ 1.76 × 10¹¹ C/kg.
3. e = 1.602 × 10⁻¹⁹ C from Millikan; m = 9.11 × 10⁻³¹ kg follows from these two.
4. This value is universal, independent of cathode material.
_Source: NCERT Class 12 Physics, Ch 11 "Dual Nature of Radiation and Matter", §11.1_

Answer

{'text': '1.76 × 10⁷ C/kg', 'label': 'B'}

Answer

{'text': '1.60 × 10⁻¹⁹ C/kg', 'label': 'C'}

Answer

{'text': '9.11 × 10⁻³¹ C/kg', 'label': 'D'}