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The electric potential at a certain dist...

The electric potential at a certain distance from a point charge is 600 V and the electric field is `200 NC^(-1)`. Which of the following statements will be true?

A

The work done in moving a point charge of `1muC` from the given point to a point at a distance of 9 m will be `4 xx 10^(-4)J`.

B

The distance of the given point from the charge is 3 m.

C

The potential at a distance of 9 m will be 200 V.

D

The magnitude of charge is `0.2 xx 10^(-3)`C.

Text Solution

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To solve the problem, we will analyze the given information about the electric potential and electric field due to a point charge and determine which statements are true based on the calculations. ### Step-by-Step Solution: 1. **Given Information:** - Electric potential (V) at a certain distance from the point charge = 600 V - Electric field (E) at that point = 200 N/C 2. **Formulas:** - The electric field (E) due to a point charge (Q) at a distance (R) is given by: \[ E = \frac{kQ}{R^2} \] - The electric potential (V) due to a point charge (Q) at a distance (R) is given by: \[ V = \frac{kQ}{R} \] where \( k \) is the electrostatic constant \( (k = 9 \times 10^9 \, \text{N m}^2/\text{C}^2) \). 3. **Setting Up the Equations:** - From the electric field: \[ E = \frac{kQ}{R^2} \quad \text{(1)} \] Substituting \( E = 200 \, \text{N/C} \): \[ 200 = \frac{kQ}{R^2} \] - From the electric potential: \[ V = \frac{kQ}{R} \quad \text{(2)} \] Substituting \( V = 600 \, \text{V} \): \[ 600 = \frac{kQ}{R} \] 4. **Dividing Equation (1) by Equation (2):** \[ \frac{E}{V} = \frac{\frac{kQ}{R^2}}{\frac{kQ}{R}} \Rightarrow \frac{E}{V} = \frac{1}{R} \] Substituting the values: \[ \frac{200}{600} = \frac{1}{R} \Rightarrow \frac{1}{3} = \frac{1}{R} \] Therefore, \( R = 3 \, \text{m} \). 5. **Finding the Magnitude of Charge (Q):** - From equation (2): \[ 600 = \frac{kQ}{3} \] Rearranging gives: \[ kQ = 600 \times 3 = 1800 \] Thus: \[ Q = \frac{1800}{k} = \frac{1800}{9 \times 10^9} = 0.2 \times 10^{-6} \, \text{C} = 0.2 \, \mu\text{C} \] 6. **Finding Potential at a Distance of 9 m:** - Using the formula for potential: \[ V_{9m} = \frac{kQ}{9} \] Substituting the values: \[ V_{9m} = \frac{9 \times 10^9 \times 0.2 \times 10^{-6}}{9} = 0.2 \times 10^3 = 200 \, \text{V} \] 7. **Calculating Work Done in Moving a Charge:** - The work done (W) in moving a charge \( q \) from potential \( V_A \) to \( V_B \): \[ W = q(V_A - V_B) \] Given \( q = 1 \, \mu\text{C} = 1 \times 10^{-6} \, \text{C} \), \( V_A = 600 \, \text{V} \), and \( V_B = 200 \, \text{V} \): \[ W = 1 \times 10^{-6} (600 - 200) = 1 \times 10^{-6} \times 400 = 4 \times 10^{-4} \, \text{J} \] ### Conclusion: - The distance of the given point from the charge is **3 meters** (Option B is correct). - The potential at a distance of **9 meters** is **200 V** (Option C is correct). - The magnitude of the charge is **0.2 µC** (Option D is correct). - The work done in moving a point charge of **1 µC** is **4 x 10^-4 J** (Option A is correct).

To solve the problem, we will analyze the given information about the electric potential and electric field due to a point charge and determine which statements are true based on the calculations. ### Step-by-Step Solution: 1. **Given Information:** - Electric potential (V) at a certain distance from the point charge = 600 V - Electric field (E) at that point = 200 N/C ...
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