Neon lights are an example of light produced as a result of an electrical discha
ID: 2280047 • Letter: N
Question
Neon lights are an example of light produced as a result of an electrical discharge in a tube filled with a gas, which emits a characteristic color (see figure below). The light emitted by discharge tubes is important in the study of atomic physics. To produce the electrical discharge, a high voltage must be applied to electrodes sealed in the ends of the tube. The resistance of a tube is 1.37 times 106 ? and the rms current through it is 3.12 mA. The transformer used to produce the high voltage is plugged into a standard electrical outlet. Find the ratio of the number of turns in the secondary to the number of turns in the primary. (The voltage supplied to the transformer is 120 V.)Explanation / Answer
primary Voltage
Vp=120 V
secondary Voltage
Vs =IR=(3.12*10^-3)*(1.37*10^6)
Vs=4274.4 Volts
transformer turns ratio
Ns/Np =4274.4/120
Ns/Np=35.62 =36 (approx)