In an experiment to determine the charge to mass ratio e/m of the electron using a cylindrical diode, the following equation is derived: e/m=8V/(r^2 B^2 ), where V is the potential difference across the diode of radius r at the critical field B. The latter is supplied by passing a current I through a solenoid of diameter D and length L, and is given by B = (μ_0 nI)/(I+D^2/L^2 )^(1/2) , where n is the number of turns per unit length. The appropriate experimental quantities are determined as follows: n = 3920 m–1; D = 0.035 + 0.001 m; L = 0.120 + 0.001 m; r = (3.4 + 0.1) × 10–3 m; 1 = 1.92 + 0.02 A; V = 20 + 1 V. Value of e/m: (a) 1.6 × 10 11 C/kg (b) 1.7 × 10 11 C/kg (c) 1.8 × 10 11 C/kg (d) 2.7 × 10 11 C/kg

In an experiment to determine the charge to mass ratio e/m of the electron using a cylindrical diode, the following equation is derived: e/m=8V/(r^2 B^2 ), where V is the potential difference across the diode of radius r at the critical field B. The latter is supplied by passing a current I through a solenoid of diameter D and length L, and is given by B = (μ_0 nI)/(I+D^2/L^2 )^(1/2) , where n is the number of turns per unit length. The appropriate experimental quantities are determined as follows:
n = 3920 m–1; D = 0.035 + 0.001 m; L = 0.120 + 0.001 m;
r = (3.4 + 0.1) × 10–3 m; 1 = 1.92 + 0.02 A; V = 20 + 1 V.

 

Value of e/m:

        (a)    1.6 × 10¹¹ C/kg

        (b)    1.7 × 10¹¹ C/kg

        (c)    1.8 × 10¹¹ C/kg

        (d)    2.7 × 10¹¹ C/kg