Q1. Fill in the blanks.
i. The ____________ of earth's crust are in continual motion.
ii. Like charges ______ and unlike charges _________ each other.
iii. In an electroscope, the aluminium leaves diverge because like charges ________.
iv. ___________ is provided in buildings to protect us from electrical shocks due to any leakage of electrical current.
v. ___________ is also an electric spark, but on a huge scale.
vi. The outermost layer of the earth is not in one piece. It is fragmented. Each fragment is called a ____________.
Q2. State True (T) or False (F).
i. Like charges attract each other. _____
ii. A charged glass rod attract a charged plastic straw. _____
iii. Lightning conductor cannot protect a building from lightning. _____
iv. Earthquakes can be predicted in advance. _____
v. An earthquake of magnitude 6 has thousand times more destructive energy than an earthquake of magnitude 4. _____
vi. Earthquakes tend to occur at the boundaries of earth’s plates. _____
Q3. List three states in India where earthquakes are more likely to strike.
Q4. How will you charge a glass rod by the method of friction?
Q5. What are the two kinds of electric charges?
Q6. What is a flash of light which occurs in the sky during the rainy season called?
Q7. How a ballpoint pen refill can be charged by the method of friction?
Q8. What are the three layers of earth?
Q9. What happens when two like charges are brought together?
Q10. What is the purpose of the Richter scale?
Q11. What is directly below the epicenter of an earthquake?
Q12. What kind of electric charge is acquired by a plastic comb rubbed with dry hair?
Q13. How an inflated rubber balloon can be charged by the method of friction?
Q14. What is focus of an earthquake?
Q15. What is the instrument used to measure and record an earthquake?
Q16. What is epicentre of an earthquake?
Q17. What type of electric charge is acquired by a rubber balloon when rubbed with a woolen cloth?