# Electric Field Mapping Apparatus

Item no.: F17

##### Introduction

Base on Coulomb’s law, the magnitude of electric field E produced by single charge Q might be given below, which induce an irradiated outward electric field for + Q or irradiated inward direction of electric field for – Q.

While consider the work done of charged particle moving in the electric field, the resultant potential difference might be formulated as below. Here the direction normal to measured equipotential lines, Vi =0, Indicate the intended electric field(as shown of dash line), in other words, the distributions of eletric field might be also concluded if the profile of equipotential lines is determined.

The designed device of smaller size, economical cost and easy-to-use offers a single conductor-bar shifting on the testing board of graphite, embedded in plastic plates with four popular patterns, permanently printed on in highly conductive paint to constitute the Wheatstone-bridge circuit, and then various equipotential lines, induced by different dipoles, might be easily outlined by individual contour with equal sub-potential accessed using single conductor-bar. In this subject, experimental knits will help us visualize the pattern of electric field (line of electrostatic force) which are orthogonal to the distributed equipotential lines measured from various aspects of electric dipoles.

##### Objectives
1. Parallel plate capacitor
2. Two points within a field
3. Point and plane
4. The lighting rod
##### 實驗項目：
1. 二個不同形狀帶電體周圍的等電位線與電力線
2. 三個點狀帶電體其周圍的等電位線與電力線
##### 實驗器材：
1. 印刷含銀電極及石墨膠紙導電板x4 – 以內含導電石墨材質之塑膠紙, 其上印刷有非導電材質之點方格及高 電極上中心處皆有一雙向導線銅製插座, 尺寸26x17x0.5cm, 可固定於絕緣基座上.電極板有四片。（ 雙平行長直電極x1、雙圓點電極x1 、一長直一圓點電極x1、避雷針之尖端放電模型x1）
2. 絕緣基座 x1 – 乾燥木製29x20x2cm,含四絕緣鋁柱
3. 長U型導電測試棒x1 – 鋁製,外層絕緣,內層導電,含低摩擦導電滾珠,尺寸: 27×2.5x4cm
4. 短固定式U型導電電極x1
5. 長固定式U型導電電極x1
6. DC電池盒 1.5/3/4.5/6/7.5/9V x1
7. 導線x5
8. 三用電錶x1