A microscopic dust particle has a specific charge of -4.80 × 10-3 C kg-1. It is held stationary in a uniform vertical electric field near the surface of the Earth.
What are the magnitude and direction of the electric field?
4.89×10−4 V m−14.89 \times 10^{-4}\text{ V m}^{-1}4.89×10−4 V m−1 upwards
4.89×10−4 V m−14.89 \times 10^{-4}\text{ V m}^{-1}4.89×10−4 V m−1 downwards
2.04×103 V m−12.04 \times 10^3\text{ V m}^{-1}2.04×103 V m−1 upwards
2.04×103 V m−12.04 \times 10^3\text{ V m}^{-1}2.04×103 V m−1 downwards
