18.2 Uniform electric fields

In a uniform field, field strength magnitude is E=∆V/∆d, where ∆V is potential difference across perpendicular separation ∆d.

Use metres and volts, and remember field direction points from higher potential toward lower potential for a positive test charge.

A 600 V difference across 0.020 m gives E=3.0×10⁴ N C⁻¹.

The relation is for a uniform field; in a point-charge field strength changes with distance.

A charge in a uniform field feels F=qE, so if q and mass are constant its acceleration is constant and directed with or against E according to charge sign.

Resolve initial velocity into components: the field changes the component along its force while perpendicular motion remains uniform in the ideal model.

An electron entering a uniform vertical field follows a curved path because horizontal velocity persists while vertical acceleration acts.

A negative charge accelerates opposite the field direction; the field does not automatically stop all motion.