This paper presents the development of a conductive gel that can be used to measure the electrical potential differences on its surface, and has enough consistency to plot equipotential lines. It has a gelation time of less than 10 min, and is suitable for implementing learning experiences in a physics teaching laboratory in a 90 min session. To evaluate the gel, voltage measurements were made on its surface by applying an alternating electric current with frequencies of 60 and 1000 Hz and an amplitude of 200 mV using iron steel electrodes with several geometrics. Some equipotential lines were also identified using a water soluble marker.