Questions

"CD-ROM is a semiconductor memory" is a FALSE statement.

Compact Disc-Read-Only Memory, a type of optical disk capable of storing large amounts of data -- up to 1GB, although the most common size is 650MB (megabytes). A single CD-ROM has the storage capacity of 700 floppy disks, enough memory to store about 300,000 textpages.

Semiconductor memory is a type of semiconductor device tasked with storing data. There are two electronic data storage mediums that we can utilize, magnetic or optical.

Magnetic storage:

* Stores data in magnetic form.

* Affected by magnetic fields.

* Has high storage capacity.

* Doesn't use a laser to read/write data.

* Magnetic storage devices are; Hard disk , Floppy disk, Magnetic tape etc.

Optical storage:

* Stores data optically, uses laser to read/write.

* Not affected by magnetic fields.

* Has less storage than a hard disk.

* Data accessing is high, compared to a floppy disc.

* Optical storage devices are; CD-ROM,CD-R, CD-RW, DVD etc.

There is also volatile memory. This is memory that loses its data once power is cut off, while non-volatile memory retains data even without power.

Total value = 4 + 2 + 2 + 3 = 11.

The lens which have atleast one inward curved surface is a concave lens. Concave ens is a diverging lens as it spreads out light rays that have been refracted through it.

A concave lens is thinner at its centre than at its edges.

Aestivation is summer sleep. Many organisms like the snails do not find it comfortable in summer. They withdraw and lead a life with reduced BMR (basic Metabolic Rate) in a state of  dormancy.