一、要点解读(一)如何判断物体有无磁性判断物体是否有磁性可以从吸铁性、指向性、磁极间的相互作用规律、磁体的磁性强弱分布特点来进行解答.1.根据磁体的吸铁性判断.分别将钢棒靠近无磁性的铁类物质,如铁屑、大头针等,若能够吸引,则钢棒有磁性,否则没有磁性.2.根据磁体的指向性判断.分别将钢棒用细线吊起,使它们能在水平面上自由转动,若静止时总是指示南北方向说明钢棒 First, the point of interpretation (a) how to determine whether the object has a magnetism to determine whether the object magnetism can be from the iron absorption, directivity, the interaction between the magnetic law, the magnetic characteristics of the distribution of magnetic strength to answer.1.According to the magnet Determine the iron absorption.Will be close to the non-ferrous iron rod material, such as iron, pins, etc., if able to attract, the steel bar has magnetic, or no magnetism .2 According to the magnetic orientation of the judge. The rods are lifted with thin wires so that they can rotate freely in the horizontal plane, always pointing north-south if stationary