Write a note on accuracy and precision. False Figure 4. Answer: This LED has an maximum intensity of 200 mcd, which means it's just bright enough to … Amount of substance is With the current reading, you should be able to get the number of excited electrons, which should correspond to the number of photons that hit the given surface area of your material. Which one the following system of units is the British System of unit? (d) SI Question 5. Answer: The shorter the distance the bigger the discrepancies between the data calculated according to this law and measured. Med. Precision : Precision is the closeness of two or more measurements to each other. time. Question 2. Assertion : Radian is the angle subtended at the centre of a circle by an arc whose length is equal to the radius of the circle. Quantities other than base quantities are called as The difference between the real value and the observed value is called an error. These clocks are making use of periodic vibrations occurring within the atom. 57 (2012) 6661–6670. Correct statement: But I suppose any book dealing with radiation could help as inverse square distance law is a general law. How much UV-light exposure time is required to disinfect a laminar flow hood? of Ultraviolet Light Emitting Diodes UV-LEDs are narrow band sources. Irradiance obeys the inverse distnace square law. When i check for Uv-C lamp providers their data is given in UV output ( in Watts ) but for selection of suitable lamp, i will need data of UV Irradiance ( watts sec / cm2) . (b) Both assertion and reason are true but reason is not the correct explanation of the assertion Temperature is a measure of total kinetic energy of the particles in a system. Originated from the term candles, candela refers to luminous intensity; how strong is the light to a naked eye; The higher the luminous intensity, the higher the sensitivity it is to our eyes; Lumen. It shows ‘minute’. = -173° C, Question 3. Therefore, all fluorescent penetrants and magnetic particle materials are tuned to fluoresce under UV-A at 365 nm. Seconds Hand : It is long and very thin. Answer: Intensity describes the distribution of radiation within very small solid angles. (c) kelvin (c) Temperature, III. @ R. Grimes, Radiometric units can be tricky; radiant intensity is the power per solid angle. 3 is less than 5. It shows ‘second’. In thermometers, freezing point of water is taken as the Upper Fixed Point. It shows ‘hour’. The Earth is divided into 24 zones, each of a width of 15 degree longitude. Question 4. Question 2. Answer: So if your bulb was 10cm long with a 15 W power, you'd expect an SR of 15W/0.1 = 150 W/m. KOBRA UV Black Light Flashlight 100 LED #1 Best UV Light and Blacklight For Home & Hotel Inspection, Pet Urine & Stains - Ultra Intensity 18W 385-395nm LEDs Spot Counterfeit Money, Leaks, Scorpions! Question 5. (d) Integrated symbol of units Correct statement: Correct explanation : Kermanshah University of Medical Sciences, Please provide more details about lamp power, I have a UV- 254 nm source what will be the intensity, What I really want to know is whether or not this is suitable for curing cell-laden hydrogels. All rights reserved. Is there any other source we can use? is a physical quantity that expresses the degree of hotness or coldness of a substance. Explain the Greenwich mean time. The visual sensation of the luminous intensity of a light source. Question 6. True. Answer: (c) FPS Question 1. (c) Directly proportional to the square of number of atoms Round off the number 5.323 to two decimal places. Answer: Name the British system of units. But do I have mercury line here? Measure Ambient Light … Equally, cylinder models aren't great as the orientation UV radiation is received at matters. Answer: Given: Charge Q = 5 C For … ∴ The answer is 5.32. (a) Both assertion and reason are true and the reason is the correct explanation of the assertion. Answer: Normal temperature of the human body is between 98.4° C and 98.6° C. Answer: How can I measure its intensity in terms of wavelength? The dose = intensity * time (for the huge water treatment plant it is usually 400 J/m^2 and I will make the formula to be with that value at the end), so. Answer: Correct statement: Direction: Mark the correct choice as. (a) If both assertion and reason are true and reason is the correct explanation of the assertion. It is not mandatory to have the same intensity of light in all directions of a light … What is electric current? Question 6. Correct explanation : What are the differences between Plane angle and solid angle? A digital clock displays the time directly. Answer: These uncertainties are called as ‘Errors’. True, Question 7. Physicians use ‘clinical thermometers’. (d) Approximation Increase it by one, if the next digit is 5 or greater than 5. Time t = 20 s, Solution: Answer: See one of my articles on UV lamp modeling or my UVGI Handbook (Springer), or Modest's book. Do you want to calculate intensity or irradiance? However this law has some limitations - it works properly for large distance (when it can be assumed that source is a point). 3. Answer: The UV lamp will have an aging decay as time went by, … Accuracy : Accuracy is the closeness of a measured value to the actual value or true value. FPS – System (Foot for length, Pound for mass and Second for time), CGS – System (Centimetre for length, Gram for mass and Second for time), MKS – System (Metre for length, Kilogram for mass and Second for time). Operating parameters of powerful UV and vacuum ultraviolet (VUV) excilamps with different discharge geometry excited by capacitive discharge, barrier discharge, glow discharge, and UV-preionized discharge were investigated. Answer: Define – mole. Carbon Dioxide Molecule used as a laser medium. (d) None of the above Answer: Can anyone explain me how to calculate these two variables according to the specific needs, please? You must model the lamp body using a radiation view factor for a cylinder radiating to a point. Assertion : Avogadro’s number is the number of atoms in one mole of substance. Question 4. Angle between the intersection of three or more planes at a common point. Question 7. Answer: Answer: Solution: Only for input power between approximately zero and 0.08 W is the input power linearly related to the square of light intensity. I would like to compare the UV dose of a UV lamp 365 nm, 6 mW/cm2 at a distance of 0.5 cm with the UV dose of a UV lamp 365 nm, 250 mW/cm2 at a distance of 19 cm. Mention its SI unit and symbol. What is the value of Avogadro’s number? SI retain 2 as 2. Question 3. Answer: I am currently working on UV sanitation system. (d) Assertion is false, but reason is true] • Light intensity must be strong enough to penetrate skull & cranial tissues to reach pineal gland & hypothalamus – primarily by longer wavelengths = orange- red How can I calculate the UV dose, in J/m2? The magnitude of an electric current is the amount of electric charges flowing through a conductor in one second. My aim is to kill 90-99 % microbes on the surface in around 30-40 sec. Answer: Question 1. Question 5. The area of my sample is equal to 4.7 cm x 6.7 cm. Tungsram is a European lighting company, designs and develops light sources, from traditional technologies to LED. Mention the SI unit & symbol of temperature. Thermometer. Answer: Answer: Candela is used to express luminous intensity. (a) Both assertion and reason are true and the reason is the correct explanation of the assertion, Question 3. Answer: The magnitude of a physical quantity consists of …………….. In SI system the units are precisely defined and have the same value everywhere. You can Download Samacheer Kalvi 8th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations. Temperature is a measure of the average ……………. How to calculate the UV dose from mW/cm2, time, disance and the surface of the irradiated area? Anyway, you can take a similar approach here; essentially you're extending a point source model to an array of point sources. Question 1. (a) Directly proportional to the number of atoms Given: i = $$\frac { π }{ 180° }$$. SI unit of electric current is ‘ampere’ and it is denoted as A. You are enquiring about his absence. 1 light year = 9.46 x 1015m. Would the Wattage of a bulb (whether UV or normal lights) be the maximum radiant intensity the bulb has? UV dosage or energy density, normally measured in joules or millijoules, is the product of the UV intensity/irradiance applied and the total time that the UV light is applied. The measured peak light intensity is shown as a function of dose rate in Fig. Reason : 1 radian = $$\frac { 180 }{ π }$$ Step : 1 Identify the last digit to be kept. Question 2. In terms of number of photons (particle flux) you may calculated that. Question 10. It is in the case of  UV tube that emits UV light at 254 nm, (mercury line) having strong germicidal activity. Luminous flux is the luminous intensity at a select angle, obtained by dividing the foot-candles by 4 pi radians and measured in lumens. Average Luminous Intensity Mean Spherical Candle Power. What are errors? = 36 + 273 (c) Quintal If the distance r of the irradiated surface is 5 time bigger than the maximum dimension D of the lamp, you can use the inverse square distance law to estimate the irradaince at the point. Calculate the current? These clocks have an accuracy of one second in every 10. (b) A number and a unit, Question 3. If grow lights produce a lot of UV light (such as LEC), stay on the lower side of this range 70,000 – 85,000 lux – a lot of light, some strains thrive at this light level, but some plants (especially auto-flowering and Indica strains) lose their top leaves early under this light intensity. Answer: Define super conductors. Approximation is the process of finding a number, which is acceptably close to the exact value of the measurement of a physical quantity. In literature, I have found out an example in which they use a 370 nm wavelength with a power of 30 mW/cm2 for 3 minutes. quick buy. Question 8. rouge allure velvet luminous matte lip colour £31.00. (b) Derived quantities I have a UV light tube of 30 Watt. Luminous intensity is another term for the brightness, but it is related to the solid angle.The luminous flux in lumens can only be used to measure the total light emitted by the lamp. The experiment is actually jar teests, each can is containing 1liter water that gous through the UV light apparatus. The last row (labeled "Luminous Intensity") is a measure of how bright the LED can get. (a) A unit Question 1. Leave it the same, if the next digit is less than 5. Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory, located at Greenwich in London. Bhd., Subang Jaya, Malaysia, Dose modeling in ultraviolet phototherapy. …of UV lamps, with a unique built-in position device which automatically protects operators from exposure to UV radiation. Luminous dials are a compromise. Assertion : The SI system of units is the suitable system for measurements. Question 8. These regions are called as ‘Time Zones’. One light year is defined as the distance travelled by light in vacuum during the period of one year. Energy consumption. (a) CGS (b) Supplementary False In thermometers, boiling point of water is taken as the Upper Fixed Point. If it is wrong, try to make him to understand his mistake. Voltmeter is a device used to measure electric current. When it goes about light bulbs, wattage determines its: Brightness. Answer: Meanwhile, we strive for conserving energy to save on our utility bills. What is the SI unit of Luminous Intensity? K = C + 273 The SI unit of amount of substance is mole and it is denoted as ‘mol’. As Urszula mentions, you're seemingly looking for irradiance rather than intensity, though the convention on radiometric units if often sloppy between fields! Joahnna, is 15W the electrical power of the lamp or optical? Just wondering how we calculate the intensity. Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. Answer: Assertion : Temperature is a physical quantity. rouge coco flash colour, shine, intensity in a flash £31.00. (c) Professional quantities So, he should say that, he was affected by a fever of 100°F and it is not 100°C. Question 5. (a) Milligram Luminous intensity is the power (adjusted for human eye perception called the luminosity function) of light in a unit solid angle. of the particles in a system. Answer in a word or two (Very Short Answer). Seven. Answer: The value of every measurement contains some uncertainty. Answer: When you have the irradiance distribution at the surface and the size of the surface it is easy to estimate the dose by adapting the time of operation of the lamp. Answer: Question 6. Improved Safety with LEDs: Safety is perhaps the most often overlooked advantage when it comes to LED lighting.The number one hazard when it comes to lighting is the emission of heat. Save my name, email, and website in this browser for the next time I comment. 1. How can I know its details about intensity and wavelengths? Hi, my question is: if we know that the intensity at 15 cm is 350 µW/cm2, how we can calculate the intensity of the same bulb at a distance of 3 cm? Which of the following statements about approximation is wrong? Atomic clocks are used in Global Positioning System (GPS), Global Navigation Satellite System (GLONASS) and International time distribution services. Samacheer Kalvi 8th Science Book Solutions, Samacheer Kalvi 11th Bio Botany Solutions Chapter 12 Mineral Nutrition, Samacheer Kalvi 11th Bio Botany Solutions Chapter 10 Secondary Growth, Samacheer Kalvi 11th Bio Botany Solutions Chapter 7 Cell Cycle, Samacheer Kalvi 11th Bio Botany Solutions Chapter 8 Biomolecules, Samacheer Kalvi 11th Bio Botany Solutions Chapter 11 Transport in Plants, Samacheer Kalvi 11th Bio Botany Solutions Chapter 13 Photosynthesis, Samacheer Kalvi 11th Bio Botany Solutions Chapter 9 Tissue and Tissue System, Samacheer Kalvi 11th Bio Botany Solutions Chapter 4 Reproductive Morphology, Samacheer Kalvi 11th Bio Botany Solutions Chapter 14 Respiration, Samacheer Kalvi 11th Bio Botany Solutions Chapter 15 Plant Growth and Development, Samacheer Kalvi 12th Accountancy Solutions Chapter 6 Retirement and Death of a Partner. Biol. …………….. recognized the need of ‘Standard Units’ for physical quantities. The basic way to calculate UV dose from a UVC 15Watt bulb? Unit uW/m2 means it is not intensity but monochromatic irradiance. Convert 100 K into Celsius. Reason : They are independent of each other. (a) CGS (a) Base Question 1. 2 Pack UV LED Flood Light, 30W High Power UV Black Lights with UL Plug (3.3ft Cable), IP66 Waterproof, for Blacklight Party Supplies, Stage Lighting, Aquarium, Glow in The Dark 4.9 out of 5 stars 26 $39.99$ … (d) SI Still, with bright sunlight or under a black light in a night club, you may be able to see the … How many base quantities are included in SI system? Light intensity … For example laser diodes are microns in size and are point sources. Correct explanation : Dosage or Intensity? Luminous intensity measurements assume an object appears as a point source. With LEDs, the peak wavelength is variable and depends on the individual LEDs u… Answer: If the detector and source are not directly inclined, and there is some surface normal angle, then this matters in irradiance calculations and the above equation becomes slightly more complicated; as Researchgate doesn't allow me to use nice math formatting I won't put it here but I will link you to some papers where we derive and use it; the model works within 1% for UVR irradiance at any orientation and if you're using UV lamps I'd suggest you give it a read - I'm more than happy to answer any questions you might have on it, hope it helps! Intensity of light from a candle is approximately equal to one ‘candela’. Most photopolymers react to radiation in the ultraviolet (UV) range of wavelengths, but some visible light systems are used as well. cheers. 32°F. Using a light (lux) meter is the best way to measure light intensity – it gives us the ability to choose the optimal light intensity for an environment. The UV lamp manufacturer will provide the intensity description: 1.The center intensity at xx mm is as high as xxx μw / cm 2, and it is sufficient to measure it with an ultraviolet light meter according to this data. Answer: Seven. Answer: Reliable components, high UV intensity … Temperature is a physical quantity that expresses the degree of hotness or coldness of a substance. What is luminous intensity? Answer: How can we calculate UV light intensity or its dose? Question 4. Question 8. Answer: On the one hand, we would like to be able to tell the time in the dark without dropping a hundred large on a minute repeater. How to calculate UV Irradiance (W/m2) over a range of wavelengths provided power (in watts) is known? There isn’t a formal definition of brightness, but to most people it means how strong a light … (a) Celsius Normal temperature of the human body is between 98.4° F and 98.6° F. Question 7. What is luminous Intensity? LED Luminous intensity. Answer: C = K – 273 These clocks have an accuracy of one second in every 10b seconds. 2. Difference between Plane Angle and Solid Angle: On my desk at the university I have a book in Polish with explanation - probably it won't be helpfull. (d) kilogram, Question 4. SI unit stands for (b) A number and a unit Least count is the minimum measurement that can be measured accurately by an instrument. The unit of length in FPS system is foot. (c) Metre, Question 2. One coulomb of charge flowing per second is called ‘ampere’. (d) Inversely proportional to the square of number of atoms Your friend was absent yesterday. VII. ……………… is the process of finding an unknown physical quantity by using a standard quantity. A plot of the intensity of light at different frequencies. It makes one rotation in one minute and 60 rotations in one hour. Correct statement: What is the unit of mass in FPS system? The intersection of two straight lines gives us ………………. (d) professional luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye.The SI unit of luminous intensity is the candela (cd), an SI base unit.. Photometry deals with the measurement of visible light … (b) MKS Similarly, luminous intensity is a measure of visible power per solid angle, expressed in candela (lumens per steradian). Correct statement: (a) Base, Question 3. Quartz clocks are used in GPS Devices. Closed Installation > What is the difference between the luminous intensity and brightness of light (and all other types of electromagnetic radiations)? Write a note on approximation. Question 1. False The value of every measurement contains some uncertainty. Answer: Light intensity at the product surface, described by the term irradiance, is a measure of momentary exposure and is most often quantified in milliwatts/cm2. The normal temperature of human body is between 98.4°F and 98.6°F. Angle between the intersection of two lines or planes. Candela is used to express electric field intensity. Name some common systems of measurement. The LS126C UV light intensity meter also has an intelligent statistical function, which displays real-time value, maximum value, minimum value, average value, measurement duration, date and time. Can somebody help me with estimating the intensity? The Luminous Flux from a monochromatic source producing light at a single wavelength is easiest to determine. Peak wavelength is the most important factor when selecting an LED lamp for fluorescent inspection. STER-L-RAY ® High Intensity germicidal uv lamps are manufactured with a unique structure and large diameter quartz envelope which translates to more … The UV lamp in our lab is fixed in the cell culture hood (Ushio germicidal bulb, UVC, wavelength 253.7 nm, 15 watt, 55 volt) and I need to introduce 5J/m2 to my cells. Correct statement: (b) Centimetre It is an estimation of a number obtained by rounding off a number to its nearest place value. (ii) 100 Radian is the unit of plane angle. Question 5. How to Measure Light Intensity Using a Light Meter. For accurate calculations or smaller relations r/D simmulations are necessary. Question 3. ……………… is the closeness of the measured value to the original value. True. Luminous Intensity is the amount of visible light, that is emitted in unit area per unit ……………. Among the following, which is not an metric system? At very low temperature, around 30 K (-243.2° C), some conductors conduct electric current without any loss. (c) FPS Answer: Question 3. Answer: For example manufacturer of HNS L 36 W 2G11 says it consumes 36 W of electrical power, while optical power around 254nm is 10,8W and this is the value that should be taken into account in terms of dissinfenction. 60 minutes = 1 hr However, white LEDs are large; about 1,000 times … So, the quartz clock is more accurate than the mechanical clock. The CGS, MKS and SI units are system of units. Answer: Rules for rounding off: Question 8. Answer: What are the rules for rounding off a number? Question 1. Amount of substance is a measure of the number of entities (particles) present in a substance. ……………. (d) IR light If a light source emits light with equal intensity towards all directions, total luminous flux emitted by the light is. Question 4. Write a short note on different types of clocks. Answer: How to control the radiation dose? Luminous intensity typically is represented by the symbol I ν, where the subscript ν denotes a photometric quantity, and its unit is the candela, an SI base unit (1 cd = 1 lumen/steradian, where the … The SR quantity in the answer I gave above is in fact the linear power density of the source, with units of W/m. Answer: One ampere is defined as one ‘coulomb’ of charge moving in a conductor in one second. The unit of mass in CGS system is gram. Question 10. How can i calculate the UV Irradiance from UV output ( watts) ? If your detector is directly focused on a lamp of length, E = (SR/d) [ (L-h)/(sqrt(d^2 + (L-h)^2))  + h/sqrt(d^2 + h^2)  ]. Amount of substance gives the number of particles present in the substance. Norwegian University of Life Sciences (NMBU), I have this UV lamp to use in my water treatment experiment. Candela (cd). AISIRER Alexa Smart Bulb WiFi Light Bulbs E27 Screw, 2 Pack, 10W 1000LM, App or Voice Control, 90W Dimmable White and RGBCW Colour Changing Light Bulb, Works with Alexa, Google Home, No Hub Required 4.3 out of 5 stars 1,974 Question 4. Contents: - Effect of Ultraviolet - UV-C Production - Ultraviolet Dose - Dose/Destruction Relationship - Applications - Medium and High Pressure Arc Tubes - Low Pressure Lamps - Irradiation Chambers - Single Arc Tube Configuration - UV Intensity … UV free Light Therapy Lamp: Miroco Light Therapy Lamp has an intensity of 10,000 lux in a pure white color 6500K that’s designed to imitate the daylight at noon. False These clocks are activated by ‘electronic oscillations’, which are controlled by a ‘quartz crystal’. Density of states calculation will shed some more light on the photoexcitation process, as direct correspondence of 1 photon-1 electron excitation need review at a deeper level. Mention the SI unit of luminous flux. Reason : The SI unit of temperature is kelvin. Answer: Approximations are usually based on certain assumptions having a scientific background and they can be modified whenever accuracy is needed. Reason : Least count is the maximum measurement that can be measured accurately by an instrument. This value is the intensity at (15cm) and the intensity change with the distance. Question 6. The coldness or hotness of a substance is expressed by …………….. …………….. is used to measure electric current. Write its formula and unit. A computational simulation of reflector and tube, effects in ultraviolet phototherapy, Phys. This is my goal. For the 5D distance discrepancy in irradiance (or illuminance) casued by difference in the shape of the source in relation to the point source is below 1%. (c) International symbol of units High Intensity Germicidal Ultraviolet Lamps. The device’s large OLED display provides both numerical and graphical … Answer: Intensity … Answer: In general inverse square distnace law is the solution for simplified calculations. Question 2. Question 5. When the data are inadequate, physicists are in need of an approximation to find the solution for problems. Pound. It is also important to know the dimensions of the lamp as well as the radiation pattern (radiant intensity distribution). The angle at which the rays from the sun hit the Earth determines this intensity. The JLT800 UV meter simplifies measurement by continuously sampling until UV light is detected, then automatically measuring. To calculate irradiance, this depends on your source; if it is just a 'perfect' bulb, then you can in theory use a point source. Features. Multiplying the intensity of the light opposite the mirror and the new solid angle would still give 126 lumens of luminous flux. One time. The two types of photoluminescence familiar to most of us are fluorescence and phosphorescence. False (v) 100, Question 1. Base Quantities and Units: Question 2. In TUNGSRAM Innovation is our Heritage How can i calculate UV irradiance value ? Reason : One radian is the angle subtended at the centre of a circle by an arc of length equal to its radius. Analog clocks: (a) International system of units (b) MKS Upon irradiation, these materials undergo a chemical reaction to become solid. Answer: The intensity of the light would double to 20 candelas, but the solid angle would halve to 2π steradians. Since intensity is the number of photons hitting per unit area, you can shine your UV light on a material with desirable band gap and do a photoelectric effect experiment to measure the current. Physics is the study of nature and natural phenomena. The number of lumens per square meter is called lux . (b) UV light On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when the Sun is above the horizon.When direct solar radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light … False It has three hands to show the time. Given that a UV bulb with 2x15 Watt, wavelength of 365nm, the intensity at 15cm is 2300uW/cm2. (a) Millimetre Your email address will not be published. (a) directly proportional to the number of atoms, Question 5. Question 2. The brightness of a laser beam is most closely associated with the radio-metric concept of radiance. (b) If both assertion and reason are true, but the reason is not the correct explanation of the assertion. Mention the types of clocks based on their display. What is measurement? How many base quantities are there? Below about 5 × 10 12 rads/sec the light intensity is a linear function of dose and independent of dose rate. Closeness of two or more measured values is called as Types of clocks based on display: 1. Question 9. Radiant Intensity is a measure of radiometric power per unit solid angle, expressed in watts per steradian. (a) Electric current It shows the time in numerals or other. Answer: Question 1. (c) Derived Assertion : The SI unit of temperature is kelvin. These conductors are known as ‘SUPER CONDUCTORS’. Solution: Actually the point is: does the bigger distance (19 cm vs 0.5 cm) compensate the higher energies (250 mW/cm2 vs 6 mW/cm2)? When 5 coulomb of charge, flows through a circuit for 20 seconds. (d) Unit and its symbol (c) A number Define – Temperature. Define amount of substance. (c) FPS, Question 2. One coulomb of charge flowing per minute is called ‘ampere’. When the formulas for penetrants and magnetic particle materials were created, the default UV-A source was mercury-vapor, which produce a single UV-A peak at 365.4 nm, the elemental emission line of mercury. The number 4.582 can be rounded off as 4.58. Yes, for non-negligible intensity glow, although you will need a UV light to see the true degree of fluorescence. (a) Laser light Answer: Question 3. Emits far energy at 10,600 nm (10.6 µm). Question 3. Answer: Or the distribution of wavelengths and frequencies. (d) Energy quantities No. Above this rate of … Answer: True or False – if false give the correct statement. Question 7. Scientists are using thermometers with kelvin scale. Différent types of clocks based on working mechanism: Question 1. Question 1. (a) Both assertion and reason are true and reason is the correct explanation of the assertion. Innoscience Research Sdn. List out the base quantities with their units. 1. I plan to use a UV lamp to create DNA breaks in the cells. So, we need light in a kitchen or bathroom to be bright enough to solve multiple daily tasks. C = 100 – 273 Wavelength is 254 nm? Answer: Answer: Figure 5 shows that at high input power, light intensity reaches a maximum as the LED reaches saturation. Question 2. True. (b) Fahrenheit Question 9. (c) If the assertion is true, but the reason is false. Answer: Effective intensity is defined as luminous intensity (cd) of a steady light having the same relative spectral distribution as the flashing light, which would have the same luminous range (or visual range in aviation terminology) as the flashing light … © 2008-2021 ResearchGate GmbH. … We generally denote the luminous intensity with the capital letter I. Control gear must include end-of-life protection (IEC60662, IEC 62035) Please mention the source of UV-B. Reason : Thermometers are calibrated with some standard scales like Celsius, fahrenheit and kelvin. Answer: I = $$\frac { Q }{ t}$$. Minutes Hand : It is long and thin. The magnitude of an electric current is the amount of electric charges flowing through a conductor in one second. (c) Error I = 0.25 A, Question 4. The frequency of a vibrating crystal is very precise. In this zone a high intensity UV-C is realized without having too high intensities below 2,0 m. Because of the presence of natural or mechanical ventilation in the room, the contaminated room-air will pass through the UV-C zone and thus will be disinfected.