Questions

Hair grows everywhere on the skin except palms, sole of feet and lips on the human body. Hair is modified type of skin.

When you compress or stretch a spring, as soon as the stress is relieved, the spring attains its normal shape instantly. Its Elastic potential energy helps it do so. Generally, these elastic substances follow the Hooke’s law.

According to this Law, the force needed to change the shape of spring is proportional to the displacement of the spring. The displacement referred here is how far the spring is compressed or stretched from its normal shape. Mathematically, Hook’s Law can be summarised as F= – k x. Here ‘k’ is the spring constant and ‘x’ is the displacement.

Alternating Current (AC) is the current in which flow of current is altered periodically whereas in DC current i.e, direct current the flow of current is only in one direction.

Some of the sources of AC current are :

1. Hydro-electric generators

2. Thermal power generators

3. Nuclear  power generators...

The compound with the molecular formula P4O10 is called Phosphorus pentoxide or tetraphosphorous decoxide. It is an anhydride of the Phosphoric acid.

In chemistry, the term transition metal has three possible meanings: The IUPAC definition defines a transition metal as "an element whose atom has a partially filled d sub-shell, or which can give rise to cations with an incomplete d sub-shell".

Any of the set of metallic elements occupying a central block (Groups IVB–VIII, IB, and IIB, or 4–12) in the periodic table, e.g. iron, manganese, chromium, and copper. Chemically they show variable valency and a strong tendency to form coordination compounds, and many of their compounds are coloured.

Here in the given options, only iron (Fe) is a transition metal since Strontium is an alkaline earth, arsenic is a metalloid, hydrogen is (normally) a diatomic gas.

The nucleotides that are present in DNA molecule are 4. They are Thymine (T), Guanine (G), Adenine (A) and Cytosine (C).

Here in this Adenine pairs with Thymine (A - T) and Cytosine pairs with Guanine (C - G).

In physics, the dynamo theory proposes a mechanism by which a celestial body such as Earth or a star generates a magnetic field.

Earth's crust core contains a large amount of iron and nickel is the evidence of the dynamo theory.