Answer: Option B. -> Copper rod
:
B
Only non-conducting materials can be easily charged by friction. Copper is a highly conducting material. Therefore, a copper rod cannot be charged easily by friction.

Answer: Option B. -> Earthquake
:
B
Among cyclone, thunderstorm, earthquake and floods, we cannot predict the occurrence of earthquakes beforehand.
Cyclones have a point of origin and they take time to reach the location where they cause destruction. Formation of cyclones and thunderstorms can be predicted with the weather conditions in a region.
Floods are the consequence of incessant rains or rising water levels in the water bodies in the region. Hence, they can be predicted.

Answer: Option B. -> epicentre
:
B
Epicentre is the point on the earth's surface directly above the origin of the earthquake.

Answer: Option B. -> They acquired the opposite kind of charges.
:
B
When you rub one material to another, they arechargedby friction,also like charges repel and unlike charges attract each other. In the above experiment, the balloon has acquired a kind of charge that is opposite to the charge acquired by the ballpen refill. As unlike charges attract each other, the balloon and the refill developed a force of attraction with each other, so they acquired opposite kind of charges.

Answer: Option A. -> True
:
A
Lightning is an electric spark but on a huge scale. Lightning is a sudden electrical discharge that occurs in a thunderstorm. It is caused by the accumulation of charges in the clouds. The process of electric discharge can occur between two or more clouds or between clouds and the Earth.

Answer: Option B. -> Lightning
:
B
Lightningis a sudden electrical discharge that occurs in athunderstorm. The process of electric discharge can occur between two or more clouds or between clouds and the Earth.

Answer: Option B. -> leakage of electric current
:
B
Earthing is the process of creating an alternative path for the flow of fault/excessive currents safely into the ground. Earthing is provided in buildings to protect us from electrical shocks due to any leakage of electric current in any appliance.

Answer: Option B. -> False
:
B
Lightning can strike telephone cords, electrical wires and metal pipes during a thunderstorm, so contact with these should be avoided. It is safer to use mobile phones and cordless phones. However, it is wise not to call up a person who is receiving your phone through a wired phone.

Answer: Option A. -> Crust
:
A
Earthquakes are caused by tremors due to the shaking of ground. These tremors are caused by disturbances caused in the tectonic plates. These plates aredeep down inside the uppermost layer of the earth called the crust.

Answer: Option C. -> Accumulation of charges in clouds
:
C
Lightning is caused due to the accumulation of charges in the clouds. As the charge density in the clouds increases, air can no longer stop the flow of charges and lightning strikes. The process of electric discharge can occur between two or more clouds or between clouds and the Earth.