It consists of two gold wires with thickness of 500 micron and 1. Using data obtained through the bombardment of an alkali metal. In the light emitting diodes leds methods, we first make a complete circuit, using various apparatus fig1. Shockley equation plot and fit for blue 436nm light. Use an led to give electrons energy aka excitation by electrical means. One of the most important experiments from the early 20 th century was the photoelectric effect experiment. First photoelectric effect apparatus used today showing the mercury light source right and. Millikan made the first measurement of plancks constant in 1916. Plancks constant are concepts that embrace both the chemistry that the physics. Introduction lightemitting diodes leds convert electrical energy into light energy. Experimental determination of plancks constant using. Vicky yumnam 6th semester student of 201617 in theory section a minor mistake. This experiment uses a mercury lamp to generate the photons incident on the light sensitive material.
Experimental set for measuring the plancks constant using led. The schematic for the circuit used in the experiment. The purpose of this lab activity is to determine planck s constant by measuring the turnon voltage of several leds 1. To determine planck s constant h from the stopping voltages measured at different frequencies wavelengths of light. Light of a specific frequency f passes through a ring. Experimental determination of plancks constant h 6. The plancks constant from our experiment was found to be 6.
Determination of plancks constant using photo electric. From this, we calculate the constant of proportionality he as well as the constant o. In this experiment, you will use light emitting diodes leds to measure. In this experiment, the above relationship is used to determine plancks constant h. Determination of plancks constant using the photoelectric effect mit. The existence of a smallest unit of light energy is one of the foundations of quantum mechanics. Two crystals, sodium chloride nacl and lithium fluoride lif, were used in the experiment to provide different bremsstrahlung continuums, with the hope that they could converge on the same value of planck s constant. Pdf experimental determination of plancks constant using light. Pdf the aim of this experiment was to utilize the inquiry based science education, ibse in order to offer the students a better understanding. Experimental physics extrapolation of the bremsstrahlung. Plancks constant h as the constant of proportionality. Determination of plancks constant and work function of. Experimental determination of plancks constant ifscusp.
Read the experiment and answer the following questions. This is a method using leds to estimate planck s constant data book value 6. The purpose of this lab activity is to determine plancks constant by measuring the turnon voltage of several leds. The goal of our measurement is to give an estimate of the planck constant. These were placed into the crystal post, standing up with the short edges parallel to the beam path.
1340 264 1031 787 674 768 1278 1383 980 1476 1371 1395 1486 1031 791 612 870 984 570 252 278 150 333 570 707 148 434 521 538 1150 248 1020 1078 1478 199 1059 924 364 1279 665 561 197 1020