What will the magnetic compass indicate when smoothly rolling into a standard-rate right turn from an easterly heading?

When rolling smoothly into a standard-rate right turn from an easterly heading, the magnetic compass will indicate approximately the correct magnetic heading, albeit with a slight lag due to the nature of magnetic compasses. As the aircraft begins to turn to the right, the compass initially tends to lag behind the actual heading. However, because the turn is executed at a standard rate and smoothly, the compass will eventually catch up and indicate an accurate magnetic heading once the turn stabilizes.

The compass is affected by several factors, including magnetic variation, acceleration, and deceleration, but in this scenario of a standard-rate right turn from an easterly heading, the compass is designed to provide a reasonable reading as the pilot continues the maneuver. The initial delay is normal, but the overall impression is that the compass will not show a significant error if properly interpreted within the context of the turn and heading.