电磁学的“示形规则”是指所用的左手定则、右手定则、螺旋定则等。在实际运用中很不方便,学生也常常记混。我们建议将示形规则统一整理,并和运算规则结合起来。只用一个“右手”示形,即右拳定则与右手定则。右拳定则示形:将右手握成拳形,拇指伸直。或简化为“曲”与“直”,拇指记作“直”,四指记作“曲”。如图左所示。它的适用范围是常见的几 Electromagnetic “shape rule” refers to the left-hand rule, right-hand rule, spiral rule used, etc. In practice, it is inconvenient. Students often remember to mix. We suggest that the rules should be unified and combined with the rules of operation. Only one “right-handed” shape is used, that is, right-hand and right-hand rules. The right boxing rule shows the shape: the right hand is shaped into a fist and the thumb is straight. Or simplified as “qu” and “straight”, thumb as “straight”, four fingers as “qu”. As shown on the left. Its scope of application is common