Question

A proton, a dutron and an a particle with the same KE enter in a region of uniform magnetic field, moving at right angles to B. what is the ratio of the radii of their circular paths?

• A. 1 :$\sqrt { 2 }$: 1
• B. 1 : $\sqrt { 2 }$ : $\sqrt { 2 }$
• C. $\sqrt { 2 }$ :1 : 1
• D. $\sqrt { 2 }$ :$\sqrt { 2 }$: 1

Answer 1

Answer: (A)

1 :$\sqrt { 2 }$: 1

Answer 2

r_P = $\frac { \sqrt { 2 m _ { p } K } } { e B }$ r_d = $\frac { \sqrt { 2 \left( 2 m _ { p } \right) K } } { e B }$ r_a = $\frac { \sqrt { 2 \left( 4 m _ { p } \right) K } } { ( 2 \mathrm { e } ) B }$