DIFFERENCES FROM PAST PAPERS (1998)

1. Email & Snail Mail

Snail mail:
i) "Snail mail" is a term used to refer to mail that is sent in the traditional way — through the postal service — rather than by email, fax, or other electronic means of communication.
ii) It is called "snail mail" because it can be very slow, as is a snail. Snail mail generally takes 2 or 3 days to go from origin to destination, if not many more,
iii) Snail mail has gone out of fashion for simple letters, though it is still necessary for sending packages, or legal documents that require signatures.

Email:
i) Email is electronic mail which is very quick means of communication through computers and telephone line.
ii) Email can be sent instantly.
iii) With email, a message is sent directly from a user's mail program to another person's email address. Though many email messages simply contain words, they may also include photos or other digital files, such as songs, or links to websites.

2. Apes & Monkeys

Apes:
i) Apes do not have tail.
ii) Apes have rounded nasal openings.
iii) Apes generally have bigger brains and larger bodies than monkeys.
iv) Apes do not have web foot.
v) Apes are bigger in size.
vi) Apes are: Humans, Chimps, Gorillas, Orangutans and Gibbons.

Monkeys
i) Monkeys have tails.
ii) Monkeys have slanted nasal openings.
iii) Monkeys have web foot.
iv) Monkeys are smaller in terms of size
v) Monkeys are all primates non-apes and non-prosimians (lemurs)

3. Hydrostatics & Hydrodynamics

Hydrostatics:
i) Hydrostatics is a branch of science which deals with physical behaviour of liquids at rest.
ii) The consideration of liquids at rest, involves problems of buoyancy and flotation, pressure on dams and submerged devices, and hydraulic presses.

Hydrodynamics:
i) Hydrodynamics is the branch of science which deals with behaviour of liquids in motion.
ii) The study of liquids in motion is concerned with such matters as friction and turbulence generated in pipes by flowing liquids, the flow of water over weirs and through nozzles, and the use of hydraulic pressure in machinery.

4. Comet & Meteor

Comet:
i) Comet is a collection of gas, dust, and volatile ice that travel around the sun, generally in very eccentric orbit.

Meteor:
i) Meteor is a streak of light seen in the night sky signify the burning up in earth’s atmosphere of inter-planetary material.

5. Barrage & Dam

Barrage:
i) Barrages are constructed not at a much height but at a low height.
ii) Barrages are single purpose constructions i.e. for irrigation.
iii) Electricity cannot be produced in barrages.
iv) It is constructed on plains.
v) Sukkur barrage is an example.

Dam:
i) Dams are constructed at higher elevation or at a height.
ii) Dam is multipurpose. It acts as reservoir, control flood, and for irrigation.
iii) Dam is constructed to generate electricity.
iv) It is impossible at ground level.
v) Tarbella dam is an example.