A charge of 4.6 x 10-5 C is placed in an electric field of intensity 3.2 x 104

The force on a charge in an electric field is found with F = qE, where q is the charge and E is the field intensity.

F = 4.6 × 10⁻⁵ C × 3.2 × 10⁴ N/C = 14.72 × 10⁻¹ = 1.472 N, which rounds to 1.5 N.

The 10⁻⁵ and 10⁴ combine to 10⁻¹. Forgetting this and multiplying the powers wrongly is what leads to larger values such as 3.7 N or 4.2 N.