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Explain why a drop of methylated spirit on the back of the hand feels colder than a drop of water at the same temperature.
Date posted:
February 15, 2017
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State what is meant by the term 'Specific latent heat of vaporazation'.
Date posted:
February 15, 2017
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State two factors that would raise the boiling point of water to above 100oC
Date posted:
February 15, 2017
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Water of mass 3 kg, at a temperature of 90oC is allowed to cool for 10 minutes. State two factors, other than humidity, that determine the final temperature.
Date posted:
February 15, 2017
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Ice changes to water at 0oC. Equal masses of the ice and water at 0oC are each heated to 1oC. Give a reason why more heat energy is required to heat the ice.
Date posted:
February 15, 2017
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Describe the experiment to determine the specific heat capacity, c, of a block of aluminium with two holes drilled in it, to accommodate a thermometer and an electric immersion heater.
Date posted:
February 15, 2017
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Distinguish between heat capacity and specific heat capacity of a body.
Date posted:
February 15, 2017
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A 4 ohm resistor is connected in series to a battery of e.m.f. 6 V and negligible internal resistance. Determine the power dissipated by the resistor.
Date posted:
February 15, 2017
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A current I flowing through a wire of resistance R was increased seven times. Determine the factor by which the rate of heat production was increased.
Date posted:
February 15, 2017
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A heating coil is rated 100 W, 240 V. At what rate would it dissipate energy it is connected to a 220 V supply
Date posted:
February 15, 2017
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A hair drier is rated 2500W, 240V. Determine its resistance
Date posted:
February 15, 2017
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An electric heater is connected to the mains supply. A fault in the mains reduces the supply potential slightly. Explain the effect on the rate of heating of the heater.
Date posted:
February 15, 2017
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An electric bulb is rated 75W, 240V. Determine the resistance of the bulb
Date posted:
February 15, 2017
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An electric bulb with a filament of resistance 480 ohms is connected to a 240 V mains supply. Determine the energy dissipated in 2 minutes
Date posted:
February 15, 2017
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A 60 W bulb is used continuously for 36 hours. Determine the energy consumed. Give your answer in kilowatt hour (kWh)
Date posted:
February 15, 2017
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An electric heater rated 240 V, 3000 W is to be connected to a 240 V mains supply, through a 10 A fuse. Determine whether the fuse is suitable or not
Date posted:
February 15, 2017
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When a current of 2.0 A flows in resistor for 10 minutes, 15, 000 joules of electrical energy is dissipated. Determine the voltage across the resistor.
Date posted:
February 15, 2017
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State three factors that affect the capacitance of a parallel plate capacitor
Date posted:
February 15, 2017
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State the effect of decreasing the distance between the plates of a parallel plate capacitor on the capacitance.
Date posted:
February 15, 2017
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Explain how a positively charged electroscope gets discharged when the cap is touched with a finger.
Date posted:
February 15, 2017
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Light from a lamp falls on the cap of a negatively charged electroscope. It is observed that the divergence of the leaf decreases. Explain the observation
Date posted:
February 15, 2017
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In some petrol engines where sparks plugs are used, a capacitor is connected to the distributor suggest the function of the capacitor.
Date posted:
February 14, 2017
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Name two factors other than tension, which determine the frequency of sound from a stretched wire at room temperature.
Date posted:
February 14, 2017
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State the necessary conditions for interference to occur in waves.
Date posted:
February 14, 2017
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A wire is stretched between two fixed points such that when it is plucked, it produces sound. Explain why the pitch of the sound produced may become lower when the temperature of the surrounding rises.
Date posted:
February 14, 2017
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What determines the quality of a musical note?
Date posted:
February 14, 2017
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Explain how a piece of a Polaroid reduces the sun's glare.
Date posted:
February 14, 2017
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What characteristic of sound is applied in tuning pianos?
Date posted:
February 14, 2017
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Distinguish between stationary and progressive waves.
Date posted:
February 14, 2017
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State a characteristic of sound, which is determined by overtone.
Date posted:
February 14, 2017