Give reasons :
It is essential to change the tension on the vocal cords, as we produce different sound notes from our larynx.

Produce a sound 'bho…bho…' just like a dog-barking and 'meow…meow…' just like a mewing cat. Carefully notice the tension on the vocal cords, when you produce these sounds. Do you feel that the tension on the vocal cords changes when you produce these two different sounds?

Give reasons: Potential difference produces a current in the circuit.

How do we produce sound through our voice box ?

Give reasons : As the sound wave propagates from one place to the other in air, the air itself is not required to move from one place to the other.

Why do we differ from our parents?

Give Scientific reasons: The sounds generated by a tabla and sitar are different.

Give scientific reasons Why do we need different types of telescopes?

Give Scientific Reason : It is possible to produce energy from mW to MW using solar photovoltaic cells OR How can we get the required amount of energy by connecting solar photovoltaic cells?

Give scientific reasons: It is possible to produce energy from mW to MW using solar photovoltaic cells.

Give scientific reasons Why cannot we hear the echo produced in a classroom?