Question

A copper ball of density $8.0\text{ g/cc}$ and $1\text{ cm}$ in diameter is immersed in oil of density $0.8\text{ g/cc}$. The charge on the ball if it remains just suspended in oil in an electric field of intensity $600\pi\text{ V/m}$ acting in the upward direction is __________. Fill in the blank with the correct answer from the options given below. (Take $g = 10\text{ m/s}^2$)

• A. $2 \times 10^{-6}\text{ C}$
• B. $2 \times 10^{-5}\text{ C}$
• C. $1 \times 10^{-5}\text{ C}$
• D. $1 \times 10^{-6}\text{ C}$

Hint:

When converting density from $\text{g/cm}^3$ to $\text{kg/m}^3$, simply multiply by $1000$. For example, $8.0\text{ g/cc} = 8000\text{ kg/m}^3$.

Answer 1

The Correct Option is B