Question

A copper ball of density 8.0 g/cc and 1 cm in diameter is immersed in oil of density 0.8 g/cc. The charge on the ball if it remains just suspended in oil in an electric field of intensity 600π V/m acting in the upward direction is_______.
Fill in the blank with the correct answer from the options given below. (Take g = 10 m/s2)

• A. 2 × 10−6C
• B. 2 × 10−5C
• C. 1 × 10−6C
• D. 1 × 10−5C

Answer 1

Answer: (C)

1 × 10−6C

Answer 2

Using the balance of electric and gravitational forces, the charge required to suspend the ball in the oil is 1 × 10⁶ C. Hence, the correct answer is Option 3.