Question

The ratio of the specific charge (e/m) of a proton to that of an $\alpha$ particle is

• A. 1:2
• B. 1:1/4
• C. 1:4
• D. 1:1/2

Answer 1

Answer: (D)

1:1/2

Proton
Mass no. =1
Charge = +1
Specific charge =1

$\alpha$ particle
Mass no =4
Charge = +2
Specific charge = 2/4 = 0.5

Ratio = 1:0.5 = 2:1