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Electric Charges and Fields — Physics STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 SciencePhysicsElectric Charges and Fields1 Mark
MCQ
Two small spheres with masses M1​ and M2​ hang on weightless, insulating threads with lengths L1​ and L2​. The two spheres carry a charge of Q1​ and Q2​ respectively. The spheres hang such that they are level with one another and the threads are inclined to the vertical at angles $\theta_1$​ and $\theta_2$. Which of the following conditions is required if$\theta_1​=θ_2​.$
  • A
    M1 = M2​
  • B
    ∣Q1​∣ = ∣Q2​∣
  • C
    L1​ = L2​
  • D
    None of these
✓

Answer

  1. M1 = M2​

Explanation:

$\theta_1​=θ_2​,$​ if their masses are the same because the force of repulsion due to charges is the same.

The force Mg $\sin\theta$ opposes the force of repulsion. Even if Q1​ and Q2​ are different, the force of repulsion is the same for both as they are mutual.

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