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A student found that a drop of methylated spirit on the back of the hand felt colder than a drop of water at the same temperature. Explain.
Date posted:
October 11, 2017
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A heater rated 3.5 kw is used to raise the temperature of 5 kg of water through 70⁰ C. Calculate the time required. (specific heat capacity of water is 4200 J/kg K). Give your answer in minutes.
Date posted:
October 11, 2017
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An immersion heater rated 900 w is placed in a liquid of mass 4 kg. It was switched on for 20 minutes and the temperature of the liquid raised from 25°C to 35°C. Determine the specific heat capacity of the liquid
Date posted:
October 11, 2017
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A alloy of copper mass 4 kg and specific heat capacity 400 J/kg K initially at 91⁰ is immersed in water at 20⁰ C. if the final temperature is 21⁰C, determine the mass of water.(the specific heat capacity of water is 4200 J/kg K). give your answer to one decimal place.
Date posted:
October 11, 2017
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Some water of mass 4 kg, at a temperature of 100⁰ is allowed to cool for 20 minutes. State the factors that determine its final temperature.
Date posted:
October 11, 2017
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An electric kettle rated 2000 W takes 20 minutes to heat 30 kg of a liquid from 30⁰ C to 45⁰C.
Date posted:
October 11, 2017
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Ice change to water at 0⁰ C. 5 kg of ice and 5 kg of water at 0⁰ were heated separately. Give a reason why more heat energy is required to heat ice.
Date posted:
October 11, 2017
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A boy took 10 kg of water and raised its temperature to 90⁰ C. He add m2 kg of water at 20⁰ C and the mixture attained a temperature of 50⁰ C. Determine the value of m2. (Assume the containers did not get heated. Specific heat capacity of water = 4200Jkg^-1k^-1)
Date posted:
October 11, 2017
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A ball was moving in a horizontal circle of radius 0.4 m makes 16 revolution per second. Find its centripetal acceleration.
Date posted:
October 10, 2017
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Find the value of -30^0 C on the absolute temperature scale.
Date posted:
October 10, 2017
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A sample of water was found to boil above 1000 C. State two factors that could have led this observation.
Date posted:
October 10, 2017
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A battery of e.m.f 12 v and negligible resistance is connected to a 8 ohms resistor. How much power is dissipated by the resistor?
Date posted:
October 10, 2017
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Determine the resistance of a blow dryer rated 3000 w, 240 v.
Date posted:
October 10, 2017
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Determine the resistance of a bulb rated 100 w, 240 v.
Date posted:
October 10, 2017
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Calculate the energy dissipated in 5 minutes if an electric bulb with a filament of resistance 360 ohms is connected to 240 v mains supply.
Date posted:
October 10, 2017
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An energy saving bulb rated 10 w, 240 v was used continuously for 1000 hours. Determine the energy consumed giving your answer in kilowatt hour. (kwh)
Date posted:
October 10, 2017
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In waves there is the occurrence of interference. State the necessary conditions for this to occur.
Date posted:
October 10, 2017
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On carrying out an experiment it was found that a voltmeter of high resistance was more accurate compared to that of low resistance. State the reason.
Date posted:
October 10, 2017
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What is Nuclear fission?
Date posted:
October 10, 2017
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Define Nuclide
Date posted:
October 10, 2017
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Explain two dangers of electromagnetic waves.
Date posted:
October 10, 2017
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State four Properties of electromagnetic waves
Date posted:
October 10, 2017
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State four applications of X-rays in industries.
Date posted:
October 10, 2017
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State the dangers of X-rays to human body.
Date posted:
October 10, 2017
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State types of X-rays
Date posted:
October 10, 2017
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State the properties of X-rays
Date posted:
October 10, 2017
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State one use of a CRO
Date posted:
October 10, 2017
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State four advantages of a C.R.O as a voltmeter.
Date posted:
October 10, 2017
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State four properties of cathode rays
Date posted:
October 10, 2017
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State four sources of mains electricity
Date posted:
October 10, 2017