8. A magnetic field $B = B _ { 0 } \bar { j }$ exists in the region $a < x < 2 a$ and $\vec { B } = - B _ { 0 } \hat { j }$, in the region $2 a < x < 3 a$, where $B _ { 0 }$ is a positive constant. A positive point charge moving with a velocity $\vec { v } = v _ { 0 } \hat { i }$, where $v _ { 0 }$ is a positive constant, [Figure] enters the magnetic field at $x = a$. The trajectory of the charge in this region can be like, (A) [Figure] (B) [Figure] (C) [Figure] (D) [Figure] Answer (A) [Figure] (B) [Figure] (C) [Figure] (D)
Two particle of mass $m$ each are tied at the ends of a light string of length 2a. The whole system is kept on a frictionless horizontal surface with the string held tight so that each mass is at a distance ' a ' from the center P (as shown in the figure). Now, the mid-point of the string is pulled vertically upwards with a small but constant force F. As a result, the particles move towards each other on the surface. The magnitude of acceleration, when the separation between them becomes 2 x is
8. A magnetic field $B = B _ { 0 } \bar { j }$ exists in the region $a < x < 2 a$ and $\vec { B } = - B _ { 0 } \hat { j }$, in the region $2 a < x < 3 a$, where $B _ { 0 }$ is a positive constant. A positive point charge moving with a velocity $\vec { v } = v _ { 0 } \hat { i }$, where $v _ { 0 }$ is a positive constant,\\
\includegraphics[max width=\textwidth, alt={}]{e79946a0-735d-438d-ac42-5265ab72284d-04_306_579_137_1117} enters the magnetic field at $x = a$. The trajectory of the charge in this region can be like,\\
(A)\\
\includegraphics[max width=\textwidth, alt={}, center]{e79946a0-735d-438d-ac42-5265ab72284d-04_304_562_760_343}\\
(B)\\
\includegraphics[max width=\textwidth, alt={}, center]{e79946a0-735d-438d-ac42-5265ab72284d-04_308_551_760_1044}\\
(C)\\
\includegraphics[max width=\textwidth, alt={}, center]{e79946a0-735d-438d-ac42-5265ab72284d-04_307_562_1127_343}\\
(D)\\
\includegraphics[max width=\textwidth, alt={}, center]{e79946a0-735d-438d-ac42-5265ab72284d-04_302_551_1136_1046}\\
Answer\\
(A)\\
\includegraphics[max width=\textwidth, alt={}, center]{e79946a0-735d-438d-ac42-5265ab72284d-04_93_91_1508_485}\\
(B)\\
\includegraphics[max width=\textwidth, alt={}, center]{e79946a0-735d-438d-ac42-5265ab72284d-04_89_87_1512_631}\\
(C)\\
\includegraphics[max width=\textwidth, alt={}, center]{e79946a0-735d-438d-ac42-5265ab72284d-04_89_89_1512_773}\\
(D)\\