A vertical circular coil carries a constant direct current that produces a magnetic field. At the center of the coil, QQQ, the magnetic flux density is entirely horizontal, with value BHB_{\text{H}}BH. The coil is now rotated about a horizontal axis through QQQ by an angle of 24∘24^\circ24∘, so that the plane of the coil makes an angle of 24∘24^\circ24∘ with the vertical. The current in the coil remains unchanged. Determine the percentage change in the horizontal component of the magnetic flux density, BHB_{\text{H}}BH, at point QQQ caused by this rotation. Show your working.
