B. Fill in the blanks. 3. An electroscope can be used to test whether a body is a ________ or not. 5. A lightning conductor is a long rod made of either_______ or ________. 6. In an electric circuit, the______ wire carries all the current. 7. The bigger hole in a socket called_______ saves us from getting electric shocks. 8. An electric meter measures the amount of electricity consumed in units of________. 9. The flow of large amount of current through a circuit due to the contact between the live and the neutral wire is called_______
Answers
Facts that Matter
• Lightning: Lightning is an electric spark, but on a huge scale. Lightning is caused by the accumulation of charges in the cloy s.
• Some objects can be charged by rubbing with other objets.
• The electrical charge produced by rubbing is called static charge.
• There are two ]rinds of charges-positive charge and negative charge.
It i a car vention to call the charge acquired by a glass rod when it is rubbed with silk as positive.
The other kind of charge is said to be negative.
• Charges of the same kind repel each other-, while charges of different kind attract each other.
• When charges move, they constitute an electric current.
• Electroscope; It is a device that can be used to test whether an object is carrying charge or not.
Electroscope consists of closely placed two metallic (aluminium) foils or strips.
When both the strips are charged with similar charges, they repel each other and become wide on.
• Electrical charge can be transferred from a charged object to another through a metal conductor.
• Discharged: When a body loses charge to the earth or any other body, it is said to he disch.acrged.
• Earthing: The process oftransfemng of charge from a charged object to the earth is known as earthing.
• The story of Lightning:
— Lightning occurs due to r'birtg.
— During a thunderstorm, the air currents move upwards while the water droplets move downward.
This vigorous movements cause separation of charges. This leads to the positive charges collect near the upper edges of the clouds and the negative charge to accumulate near lower edges of the clouds.
— There is an accumulation of positive charges near the ground also.
— Negative and positive charges meet, producing streaks of bright light and sound. We see streaks as lightning. The process is known as electric discharge. ne process of electric discharge between different clouds or between clouds and the earth causes lightning.