Determine the current flowing through the LED. (assume an LED forward voltage of 2.1 volts) *

Identify the placement of a mercury lamp light source relative to the Pasco interferometer in Figure 2, for a Twyman-Green setup.

1. Connect the circuit shown in Figure 2-6. Turn CM switch 6 on, which modifies the gate lead of the SCR. The gate to cathode junction readings is a. normal when forward or reverse biased. b. normal when forward biased; bad when reverse biased. c. open when forward or reverse biased. d. open when forward biased; low when reverse biased. METER Figure 2-6. OK

P.1. Approximately what percentage of visible light is given off by a 100 W incandescent lamp?A. 30 percentB. 10 percentC. 80 percentD. 50 percentP.2. The ordering code for a large incandescent lamp provides information on theA. lamp power requirement, bulb type and size, and sometimes lamp color.B. lamp power requirement, bulb size and special features, and sometimes filament type.C. lamp voltage, bulb type and size, and sometimes lamp color.D. lamp voltage, bulb size and special features, and sometimes filament type.P.3. Which of the following units is used to measure the chromaticity of a lamp?A. Degrees KelvinB. WattsC. Degrees FahrenheitD. Amperes