Uses of electroplating

​Question 1 Name two metals which are usually electroplated on cheaper metals for making jewellery? Question 2 What properties of chromium make it suitable for electroplating it on car bumpers, bath taps and bicycle handlebar? Question 3 What properties of tin make it suitable for storing food? Question 4 Which is the polluting waste generated…

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Purification of metal

Question 1 Name few application of chemical effects of electric current? Question 2 Name few compounds which are produced by using chemical effect of current? Question 3 Name 2 metals which are purified by using the chemical effect of current? Question 4 Describe how you will purify a strip of impure copper by using chemical…

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Weak conductors of electricity

Question 1 How will you show that vinegar and lemon juice are weak conductors of electricity? Question 2 How will you show that ordinary water or tap water is a weak conductor of electricity? When an ​electric current is passed through vinegar taken in a beaker ,then the bulb glows very dimly. The very dim glowing…

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Electroplating

Question 1 Name few applications of chemical effect of electric current? Question 2 What is electroplating? Question 3 Name the metal which is electroplated on car parts such as bumpers and bicycle handle bars? Question 4 Which metal is electroplated on iron making cans used for storing food? Question 5 What is the purpose of…

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Chemical effect of electric current

​Question 1 Define the term chemical effects? Question 2 What is electrolysis? Question 3 What is an acidified water? Question 4 Name one compound which is decomposed into hydrogen and oxygen by using chemical effects of electric current? Question 5 What should be done to decompose water into hydrogen and oxygen? Question 6 Acidified water…

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Distilled, tap, sea and rain water

Question 1 Distilled water does not conduct electricity?Why? Question 2 What substance can be added to distilled water in small amount to make it a good conductor of electricity.Why? Question 3 Is it safe for the electrician to carry out electrical repairs outdoors during heavy downpour.Explain? Question 4 Which is a better conductor of electricity:Drinking…

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Detection of weak current flowing through liquid

Question 1 Write the full form of LED? Question 2 Name a device which glows even when a weak electric current passes through it? Question 3 What is it advantage of using LED in testing the electrical conductivity of liquids? Question 4 Which effect of electric current is utilised for detecting the flow of current…

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Test for conduction of liquid

Question 1 Describe an activity to show that hydrochloric acid solution conduct electricity? Question 2 Vinegar is a sour liquid.State whether vinegar conduct electricity or not? Question 3 Describe an activity to show that sugar solution do not conduct electricity? Question 4 How will you show that alcohol does not conduct electricity? ​Take a small beaker.Fix…

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Liquids conduct electricity

Question 1 What are good conductors of electricity?Give example? Question 2 What are bad conductors of electricity?Give example? Question 3 Do liquids conduct electricity? Question 4 What are electrolytes? Question 5 What are strong electrolytes.Give example? Question 6 What are weak electrolyte. Give example? Question 7 What is an electrode? Question 8  Name two types…

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Noise pollution

Question 1 What are causes of noise pollution? Question 2 What is the difference between noise and music? Question 3 What is partial hearing.What are the usual cause of noise pollution? Question 4 What is meant by noise pollution? Question 5 Explain how noise pollution is harmful to human beings? Question 6 State the various…

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Musical instruments

Question 1 Name the substance which vibrate in a flute to produce sound? Question 2 Name 4 types of musical instruments? Question 3 Give example of stringed musical instruments? Question 4 Give example of wind musical instruments? Question 5 Give example of membrane musical instruments? Question 6 Give example of plate type musical instruments? Question…

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Noise and music

Question 1 What is noise? Question 2 Give examples of noise? Question 3 What is musical sound? Question 4 How is noise produced? Question 5 How is musical sound produced? ​The unpleasant sounds around us are called noise. Noise is produced by the irregular vibrations of the sound producing source. For Ex: Running of mixer…

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Audible and Inaudible sound

​Question 1 Why we do not hear the screams of a bat? Question 2 What is the name of very high frequency sound which cannot be heard by human ears? Question 3 What is an audible sound? Question 4 What is an inaudible sound? Question 5 State few uses of ultrasound? Question 6 What is…

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Characteristics of sound

Question 1 How does the loudness depends on the amplitude of vibration? Question 2 By how much the loudness of sound changes when the amplitude of vibrations is doubled and halved? Question 3 Name the unit to measure the loudness of sound? Question 4 What is the loudness of normal conservation in decibels? Question 5…

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Amplitude, time-period and frequency of vibration

Question 1 Define the term vibration? Question 2 How is simple pendulum made? Question 3 What is the relation between time period and frequency of an oscillating body? Question 4 Name 3 characteristics which are used to describe oscillations? Question 5 Define the term amplitude? Question 6 How can we increase the amplitude of vibration?…

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Ears

Question 1 Draw a neat and labelled diagram of human ear? Question 2 Explain the working of human ear? Question 3 Name the organ of hearing in human being? Question 4 Name that part of ear which vibrates when outside sound falls on it? Question 5 Name the three tiny bones present in the middle…

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Speed of sound

Question 1 What is the speed of sound in air? Question 2 What is the speed of sound in water? Question 3 What is the speed of sound in solids? Question 4 Where would sound travel faster- in wood or water? Question 5 In which medium sound travel faster- air or iron? Question 6 When we put…

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Sound needs a medium for Propagation

Question 1 What does the working of a toy telephone tell us about sound? Question 2 Name ​one solid, liquid and a gas through which sound can travel? Question 3 Why sound cannot travel through vacuum? Question 4 Define the term medium? Question 5 How can you show that sound cannot travel vacuum? Question 6…

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