Class 8 Science Chapter 12 MCQ

Here, all the statements are correct. Hence, your answer will be option [D].

Here, all are insulators whereas “Copper rod” is a conductor. As soon as we charge a copper rod by rubbing with another material, the electric charge flow through our hand and body and flows into the earth. As a result, the copper rod remains un-charged.

Here, all the statements are correct. Hence, your answer will be option [D].

Two bodies must be joined by any conducting wire i.e., copper wire for the flow of current.

When we rubbed a glass rod with silk cloth, the glass rod becomes positively charged. The silk cloth becomes negatively charged. The electric charges generated by rubbing are static electric charges. These electric charges remain bound on the surface of the charged object

When the earth’s plate brush past one another or under group collision, causes earthquake. An “earthquake” can cause huge damage to buildings, dams, etc.

The electric charges generated by rubbing are static electric charges. There are two types of charges; “Positive Charge and Negative Charge”. All the objects like glass rod, silk cloth, rubber balloon, ballpoint pen etc., are made up of tiny particles called atoms. We know that positive electric charges called protons and negative electric charge is called electrons. The object which loses negatively charged electrons during rubbing, acquires a positive electric charge. The object which gains negatively charged electrons during the rubbing, acquires a negative electric charge.

Two charged objects may attract, if they carry opposite charges, while they repel. If they carry similar charges.

Tsunami refers to the powerful sea waves generated due to the disturbance under the sea. It is not likely to occur in case of lightning, because lightning is an electric spark caused by the accumulation of charges in clouds.

After rubbing the glass rod with silk cloth, the glass rod becomes positively charged. The silk cloth becomes negatively charged. When a plastic comb is dry hair, it becomes negatively charged. The negatively charged comb induces a positive charge on the pieces of paper which are neutral in nature.

Here, all the statements are correct. Hence, your answer will be option [D].

Since earthquakes are caused by the movement of plates, the boundaries of the plates are weak zones where earthquake are more likely to occur. These weak zones are also known as seismic zones or fault zones.

Here, all the statements are correct. Hence, your answer will be option [D].

The magnitude of an earthquake is expressed on the Richter scale. Richter scale is just like the decibel scale. But remember, it is not a linear scale. This means that an earthquake of magnitude 2 on Richter Scale is not 2 times as strong as an earthquake of magnitude 1. An earthquake of magnitude 2 is 10 times as strong as an earthquake of magnitude 1. An earthquake of magnitude 3 on Richter Scale is 100 times as strong as an earthquake of magnitude 1 on the same scale.

The epicentre is the point on the “earth’s surface” vertically above the hypocentre (or focus), point in the crust where a seismic rupture begins.

Major earthquakes are less likely to occur in Odisha. The most threatened areas in India are Kashmir, Western and Central Himalayas, the whole of North-East, Rann of Kutch, Rajasthan and Indo-Gangetic Plane.

During a charging by rubbing (or by friction) process, the material that becomes negatively charged does so because it simply likes or gain electrons more than the material with which it is rubbed. The conductive abilities of the two materials has nothing to do with the subsequent result of the rubbing process.

Earthquake is a sudden shaking or trembling of the earth due to the collision between the earth’s plate or brushing past of one plate over the other. It can cause Tsunami, floods and landslides.

Here, all the statements are correct. Hence, your answer will be option [D].

The process of electric discharge between clouds and the earth or between different clouds causes lightning. The tremendous electric charges in the atmosphere which produce sheet lightning in the clouds are produced by the process of “Friction”.

Here, all the statements are correct. Hence, your answer will be option [D].

Focus of an earthquake is located deep under the ground. Focus is the point inside the crust where the pressure is released. The point on the earth’s surface above the focus is called the epicenter.

A ballpoint pen refill can be charged by rubbing it against the wool cloth. It becomes negatively charged.

Here, all the statements are correct. Hence, your answer will be option [D].

The whole crust of the earth is not in one piece. The crust of earth is made up of many huge pieces of flat rocks. Each pieces of the earth crust is called a plate. The crust of earth is divided into many plates. The plates of earth on which continents exist are called “continental plates” whereas those plates of earth on which oceans exist are called “oceanic plates”.