Daily NEET MCQ- April 30, 2022 - NEET MCQ

Three quantities are needed to specify the magnetic field of the earth on its surface, namely, the horizontal component, the magnetic declination and the magnetic dip. These are known as elements of the earth’s magnetic field or magnetic elements.

A vertical plane passing through the axis of a freely suspended or pivoted magnet is known as magnetic meridian of Earth. The vertical plane passing through the geographical North Pole and South Pole at a given place is known as the geographical meridian of that place.

Molecularity of a reaction is the number of atoms, ions or molecules that must collide with one another simultaneously so as to result into that chemical reaction. It does not affect the rate of the reaction directly.

The presence of a catalyst in a reaction lowers the activation energy barrier and hence the reaction becomes faster. Hence, the addition of catalysts helps to increase the rate of a reaction.

Increasing the temperature of a reaction results in an increase in the average kinetic energy of the particles taking part in the reaction. As the kinetic energy increases, the particles move faster and collide with each other more frequently and with a higher energy. This makes it easier for chemical reactions to take place. Hence, increasing the temperature increases the rate of the reaction.

These two scientists, in their experiment showed the formation of simple amino acids and organic acids. They concluded life came from organic compounds.

Earth was formed about 4.5 billion years ago whereas life originated about 4 billion years ago. So, the time gap is about 0.5 billion years.

The active hydrogen atoms reacted with free oxygen atoms forming water. So, the primitive atmosphere was reducing without free oxygen unlike the present oxidizing atmosphere with free oxygen.

Oparin’s theory was called Naturalistic theory or Theory of chemical evolution. This theory states that life originated by the composition of chemicals, or life come from pre-existing nonliving organic.

The primitive atmosphere had no oxygen and reducing i.e. no free oxygen was available. It was converted into oxidizing nature by the emergence of cyanobacteria. They released oxygen into atmosphere by converting water into hydrogen and oxygen.