42 verified questions · ~46 minutes · answer key checked against the official NTA final key across multiple sources. Text-only questions (diagram-based excluded until they can be shown properly).
Two charged particles, placed at a distance d apart in vacuum, exert a force F on each other. Now, each of the charges is doubled. To keep the force unchanged, the distance between the charges should be changed to __________. Fill in the blank with the correct answer from the options given below.
Two charged metallic spheres with radii R₁ and R₂ are brought in contact and then separated. The ratio of final charges Q₁ and Q₂ on the two spheres respectively will be __________. Fill in the blank with the correct answer from the options given below.
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