Observe the structure of a loud speaker.
Where is the voice coil situated ?

Observe the structure of a loud speaker. From where current reaches to the voice coil?

Observe the structure of a loud speaker. To which the diaphragm is connected ?

Observe the structure of a loud speaker. What happens when current reaches through the voice coil ?

Write down the working of a moving coil loud speaker by rearranging the following in correct sequence. strengthened electrical pulses are sent through the voice coil of a loud speaker. The voice coil , which is placed in the magnetic field , moves to and fro rapidly , in accordance with the electrical pulses. The electrical pulses from a microphone. Make the diaphragm vibrate, thereby reproducing sound . Electrical pulses are strengthened using an amplifier.

Reeja, a science student, observed the structure of mature embryo sac comprising antipodals, central cells and egg apparatus. Explain each one of them.

Observe the structure.How many types of amino acids are present in animal body?

Observe the structure. In nutrition some amino acids are required. Write a note on it.

Observe the figure and answer the questions. Name the biological principles involved in the ex-change of gases in the above structure.