Techniques In Plant Analysis

A spectrophotometer directly measures the amount of light that a substance absorbs. This instrument is commonly used in scientific research and analysis to determine the concentration of a substance in a solution by measuring the intensity of light that is transmitted through it. By comparing the amount of light absorbed by the substance to a reference, the spectrophotometer can provide quantitative data on the concentration of the substance.

In a spectrophotometer, the detector is responsible for converting the light signal into an electrical signal. This electrical signal is typically in the form of current, which can be measured and analyzed to determine the intensity or wavelength of the light being detected. Therefore, the correct answer is current.

The function of a prism in a spectrophotometer is to disperse the light. When light passes through a prism, it is separated into its component colors, creating a spectrum. This dispersion allows the spectrophotometer to analyze the different wavelengths of light and measure their intensity, which is essential for various applications such as determining the concentration of a substance in a solution.

A spectrophotometer is a device used to measure the intensity of light at different wavelengths. A monochromator is a crucial component of a spectrophotometer as it allows the selection of a specific wavelength of light. It works by dispersing white light into its individual colors and then selecting a narrow band of wavelengths using a prism or a diffraction grating. This selected wavelength is then passed through the sample being analyzed. Therefore, a monochromator is used in a spectrophotometer to control and select the wavelength of light that is used for measurement.

The monochromator in a spectrophotometer is responsible for generating unilateral light of single wavelength. It achieves this by using a prism or diffraction grating to separate white light into its individual wavelengths and then selecting a specific wavelength to be transmitted through the sample. The monochromator ensures that only light of the desired wavelength reaches the sample, allowing for accurate measurement of absorbance or transmittance. The light source, on the other hand, provides the initial light for the spectrophotometer but does not generate unilateral light of single wavelength.

The correct answer is = 1 cm. In conventional spectrophotometers, the width of the cuvette is typically fixed at 1 cm. This is because a standard cuvette has a width of 1 cm, allowing for consistent and accurate measurements. The fixed width ensures that the light passing through the sample has a consistent path length, which is essential for accurate absorption measurements.

The wavelength range between 400-700 nm corresponds to the visible light spectrum. This range is commonly used to measure the absorption or transmission of light by colored solutions. Colored solutions selectively absorb certain wavelengths of light, causing them to appear colored. By measuring the amount of light absorbed within this range, we can determine the concentration or properties of the colored solution. Therefore, it is true that the wavelength range between 400-700 nm can only be used to measure colored solutions.

The law related to reciprocity is not associated with spectroscopy. Reciprocity refers to the principle that the intensity of light absorbed or emitted by a substance is directly proportional to the concentration of the substance and the path length that the light travels through the substance. However, this law is not specifically related to spectroscopy, which is the study of the interaction between matter and electromagnetic radiation. Spectroscopy involves the measurement and analysis of the interaction of light with matter, including the absorption, emission, and scattering of light.

Quartz cuvettes will be used for measurements in the range of 180-300 nm because quartz has a high transmittance in this wavelength range. Glass cuvettes have limited transmittance in the UV range, and plastic cuvettes have even lower transmittance. Therefore, quartz cuvettes are the most suitable choice for accurate measurements in this specific wavelength range.

Beer's law states that the absorbance of a colored solution is directly proportional to the concentration of the solute, not the solution as mentioned in the question. Therefore, the statement in the question is incorrect and the correct answer is False.