Concepts Of Physics MCQ Edition [Volume 2]
- Exam
- Concepts Of Physics MCQ Edition [Volume 2]
- Subject
- Physics
- Chapter
- Electric Field and Potential
Concepts Of Physics MCQ Edition [Volume 2] · Physics · Electric Field and Potential
Two particles A and B , possessing charges of +2.00 × 10^ -6 C and...
Two particles and , possessing charges of and respectively, are held fixed at a separation of . Find the point(s) on the line at which the electric potential is zero.
Options
- A from along
- B from along
- C from along
- D from along
Correct answer
C. from along
Step-by-step solution
Let be at the origin and be at a distance of from .
The electric potential at a point is given by V = \dfrac{1}{4\pi\epsilon_0} \left(\dfrac{q_A}{r_A} + \dfrac{q_B}{r_B} \right).
For , we have \dfrac{q_A}{r_A} = -\dfrac{q_B}{r_B}.
Substituting the given charges:
\dfrac{2.00 \times 10^{-6}}{r_A} = \dfrac{4.00 \times 10^{-6}}{r_B} \Rightarrow
Case 1: lies between and .
\dfrac{20}{3} \text{ cm}
This point is \dfrac{20}{3} \text{ cm} from along .
Case 2: lies outside the segment . Since , the point must be closer to , meaning it lies on the side of along the extended line .
This point is from along .
The electric potential at a point is given by V = \dfrac{1}{4\pi\epsilon_0} \left(\dfrac{q_A}{r_A} + \dfrac{q_B}{r_B} \right).
For , we have \dfrac{q_A}{r_A} = -\dfrac{q_B}{r_B}.
Substituting the given charges:
\dfrac{2.00 \times 10^{-6}}{r_A} = \dfrac{4.00 \times 10^{-6}}{r_B} \Rightarrow
Case 1: lies between and .
\dfrac{20}{3} \text{ cm}
This point is \dfrac{20}{3} \text{ cm} from along .
Case 2: lies outside the segment . Since , the point must be closer to , meaning it lies on the side of along the extended line .
This point is from along .