Class 8 Science MCQ Some Natural Phenomena

Question :Tap water is a good conductor of electricity while distilled water is not because
(a)Tap water contain salts
(b)Distilled water do not contain salt
(c)Only a) is correct
(d)Both a & b is correct

Question : When electrodes are immersed in water and electricity passed, the bubbles formed on the positive terminal is actually _______ gas.
(a)Hydrogen
(b)Carbon di oxide
(c)Oxygen
(d)Nitrogen

Question :When electrodes are immersed in water and electricity passed, the bubbles formed on the negative terminal is actually _______ gas.
(a)Hydrogen
(b)Carbon di oxide
(c)Oxygen
(d)Nitrogen

Question : A charged balloon a charged refill.
(a) attracts
(b) repels
(c) neither attracts nor repels
(d) none of these

Question :The point from where the shock waves of an earthquake originate is called
(a) epicentre
(b) seismic focus
(c) focal depth
(d) none of these

Question : When you touch a charged body, the charge flows through you into the earth. What is this called?
(a) Induction
(b) Conduction
(c) Capacitance
(d) Earthing

Question : Which of the following can be charged by rubbing?
(a) Ebonite
(b) Plastic
(c) Amber
(d) All of these

Question :Why do we add little dilute sulphuric acid to copper sulphate solution during electroplating?
(a)To increase acidity
(b)To increase conductivity
(c)So that the colour becomes more prominent
(d)To burn copper sulphate

Question :A coating of _________is deposited on iron to protect it from corrosion and formation of rust
a)copper
(b)aluminium
(c)Zinc
(d)silver

Question :Chromium plating is done on many objects such as car parts, bath taps, kitchen gas stove etc. Why?
(a)It does not corrode but prevents scratches
(b)It looks beautiful
(c)It costs less
(d)Articles can be sold at higher price

Question :The process of depositing a layer of any desired metal on another material by means of electricity is called ___________.
(a)Electric plating
(b)Electroplating
(c)Electric depositing
(d)None of the above

Question :An electric lamp glows due to
(a) Heating effect
(b) Chemical effect
(c) Magnetic effect
(d) None

Question :Electroplating prevents
(a) Rusting
(b) Current
(c) Chemical effect
(d) All

Question :Flow of electron is called
(a) Electric current
(b) Electroplating
(c) Electrodes
(d) Electrolyte

Question :Some liquids are good conductors of electricity and some are poor conductors. Which one is a poor conductor?
(a)Acidic solution
(b)Alkaline solution
(c)Common Salt solution
(d)Distilled water

Question : Tin cans, used for storing food, are made by electroplating tin onto iron. Why?
(a)Tin gives a shiny appearance
(b)To make the vessel cheap
(c)Tin is less reactive than iron.
(d)To make the vessel lighter

Question :Plastic wire is
(a) An insulator
(b) A conductor
(c) An insulator and a conductor
(d) None of the options

Question :Distilled water is
(a) Poor conductor
(b) Good conductor
(c) Poor conductor and good conductor
(d) None

Question :Poor conductors are
(a) All of these
(b) Plastics
(c) Clothes
(d) Wood

Question :Copper wire is a
(a) Good conductor
(b) Poor conductor
(c) Good conductor and poor conductor
(d) None of the options

Question :An electrolyte is
(a) A liquid that conducts current
(b) A metal
(c) A solution
(d) All of these

Question :Adding common salt to distilled water makes it
(a) Good conductor
(b) Insulator
(c) No
(d) Both Good conductor and Insulator

Question :Electroplating is based on
(a) Chemical effect of electricity
(b) Magnetic effect of electricity
(c) Heating effect of electricity
(d) Physical effect of electricity

Question : The pure piece of metal which is used to be plated, is made the
(a) anode
(b) cathode
(c) nematode
(d) posit rode

Question : Which of the following solutions is a good conductor of electricity?
(a) Glucose solution
(b) Lemon juice
(c) Alcohol solution
(d) Distilled water
(d) Vegetable oil

Question : Iron objects can be protected by electroplating them with
(a) chromium
(b) nickel
(c) zinc
(d) all of these

Question : The substance which is conductor of electricity is:
(a) rubber
(b) paper
(c) nails
(d) plastic

Question : Which of the following is a good conductor of electricity:
(a) istilled water
(b) tap water
(c) kerosene
(d) none of these

Question : A sheet of pure copper is used as
(a) cathode
(b) anode
(c) positrode
(d) negatrode

Question : Which of the following non-metals can be electroplated with copper?
(a) Sodium
(b) Iodine
(c) Silicon
(d) Carbon
(e) Phosphorus

Question : Which of the following is not used for electroplating any metal?
(a) Gold
(b) Silver
(c) Sodium
(d) Nickel
(e) Copper

Question : Copper wire is a
(a) Good conductor
(b) Poor conductor
(c) Both a and b
(d) None of this

Question : Which of the following does not conduct electricity?
(a) Sugar solution
(b) Vinegar solution
(c) Lemon juice solution
(d) Caustic soda solution

Question : Magnetic compass connected In a circuit is used to check:
(a) magnetism in electric current
(b) slow current
(c) small current
(d) none of these

Question : Waste from an electroplating factory must be disposed off
(a) in the nearby river
(b) in the nearby pond
(c) in the nearby cornfield
(d) according to the disposal guidelines of Waste Management Bodies

Question : The cans, used for storing food, are made by electroplating ___________________ on to irons
(a) chromium
(b) zinc
(c) tin
(d) none of these

Question : Adding lime water to tap water makes it:
(a) an electrolyte
(b) electrolysis
(c) no change occur
(d) none of these

Question : Waste from an electroplating factory must be disposed off
(a) in the nearby river
(b) in the nearby pond
(c) in the nearby cornfield
(d) according to the disposal guidelines of Waste Management Bodies

Question :Lightning can cause harm to our electrical instruments.

Question :Indians considered lightning as sacred.

Question :We cannot predict floods or cyclones.

Question :Electric discharge takes place between similar charges.

Question :We should avoid sitting inside the car during lightning.

Question :Lightning rod is used to save buildings from lightning strike.

Question :If the knob of charged electroscope is touched by hand then the strips revert back to their original position.

Question :Like charges attract each other.

Question :A charged glass rod attract a charged plastic straw.

Question :Umbrellas are safe during lightning.

Question :We can use the wired telephones during lightning.

Question :Silk gets positively charged when rubbed with glass rod.

Question :Earthquakes can be predicted in advance.

Question :An ebonite rod when rubbed with fur develops a ___________________.. charge.

Question :___________________.. , ___________________..can take place due to an earthquake.

Question :Interaction between opposite charges producing huge energy is called ___________________..

Question :The explosive sound heard during lightning is called ___________________..

Question :___________________.. is the process of discharging atmospheric electricity through a conductor into earth.

Question :Like charge ___________________.. and unlike charge ___________________..

Question :___________________.. electricity consists of electric charges which do not flow.

Question :Static electricity is so called because it cannot ___________________..

Question :Conventionally a glass rod acquires a ___________________.. charge on rubbing.

Question :When two bodies are charged by rubbing against each other, they acquire ___________________.. and ___________________.. charge.

Question :Due to rubbing of air particles the water droplets in clouds get ___________________.. charge.

Question :A charged balloon ___________________.. a charged refill.

Question :___________________.. showed that lightning and the spark from our clothes are essentially the same phenomena.

Question :On rubbing against each other, the bodies get ___________________

Question :A rapid flow of charge through air in clouds is called ___________________..

Question :Amber is a ___________________

Question :The electrical charge can be transferred from a charged object to another through a ___________________..

Question :Air is a ___________________.. conductor of electricity.

Question :___________________.. can not be predicted.

Question :A ___________________.. can save a building from lightning strike.