7th Science Important Q&A 2nd term 2024-25
Q.1. Write the proper words in the blanks.
(meridian, horizon,
twelve, nine, apparent, celestial, ecliptic)
(white cement, soap,
detergent, wearing of bones, tooth decay, hard, soft, Portland, fatty acid)
(stomach / mouth)
(voluntary
/ involuntary) (Production of blood cells / Performing movements) (ordinary muscles / cardiac muscles)
(stomach / oesophagus).
(1) When seen from a great distance, the sky seems to be
touching the ground along a circle. This circle is called the horizon.
(2) The ecliptic is used while defining the zodiac signs.
(3) Classified according to seasons, one season will
have nine nakshatras.
(4) The rising of the sun in the east and its setting in
the west is the apparent motion of the sun.
(5) The alloys called nipermag
and alnico are used for making industrial magnets.
(6) A magnetic field can pass through cardboard
and water .
(7) The intensity of a magnetic field is indicated by
the lines of force .
(8) The real test of a magnet is repulsion
.
(9) Sound is generated by the rhythmic vibrations
of any object.
(10) The frequency of sound is measured in Hertz
.
(11) If amplitude of sound is decreased, its loudness also decreases. (12)
A medium is necessary for propagation of sound.
(13) When the beams from the headlights of a car fall on
an object in the night, the shadows called umbra
and penumbra can be seen.
(14) During a lunar eclipse the shadow of the earth
falls on the moon.
(15) During a solar eclipse the shadow of the moon
falls on the earth.
(16) Various shades of colour are seen in the sky at
sunrise and sunset due to scattering of light.
(17) The substance that helps water to remove dirt from
the surface of materials is called detergent.
(18) Fluoride is used in toothpaste to prevent tooth decay.
(19) Soap is a salt of fatty acid and sodium hydroxide.
(20) Synthetic detergents can be used in hard
water as well.
(21) For construction purposes Portland
cement is the most commonly used cement.
(22) The process of digestion starts from the mouth.
(23) Eyelids have voluntary
muscles.
(24) Production of blood cells is not a function of the muscular system.
(25) Muscles of the heart are cardiac muscles.
(26) Pushing forward the food that has been chewed is the
function of the oesophagus.
(27) The organelle called the plastids
is present in plant cells only.
(28) Garbage is converted into fertilizers by micro-organisms.
(29) In the cell, photosynthesis is carried out with the
help of chloroplasts.
(30) An electron microscope is necessary for the study of
microbes/cell organelles.
2.
With whom should I pair up?
(a) Compass - A
magnetic needle
(b) Door of a cupboard - A magnet
(c) Repulsion - Like
poles
(d) Magnetic poles - The highest magnetic force
3. Match the pairs.
(a) Flute - Vibrations
in the air
(b) Frequency - Measured
in Hz
(c) Sound level - Decibel
(d) Ultrasonic sound - Frequency more than 20000 Hz
(e) Infrasonic sound - Frequency less than 20 Hz
4. Find a match for
me.
(1) Cardiac muscles - we never feel tired.
(2) Are brought about by muscles - chewing movements of jaws.
(3) Pepsin - enzyme
gastric juice.
(4) Cramps - uncontrolled
and painful contraction of muscles.
(5) Skeletal muscles - always function in pairs.
5. Who are my
companions?
1. Stainless steel - Alloy
2. Silver - Metal
3. Bhajani mixture for milling - Mixture
4. Salt - Compound
5. Coal - Non-metal
6. Hydrogen - Element
6. Who is telling a
lie?
Organ Statement
1. Tongue –
Answer: Tongue is telling lie. It’s taste-buds can tell all
tastes.
2. Liver -
Answer: Liver is telling truth. Liver is the largest gland in
the body.
3. Large intestine:
Answer: Large intestine is telling lie. Large intestine is 1.5
meter long.
4. Appendix:
Answer: Appendix is telling lie. Appendix has no role in
digestion.
5. Lung:
Answer: Lung is telling partially lie. Lung does not play as
important role as kidney in excretion.
7. Write the names of
elements from the following symbols:
Zn - Zinc Cd - Cadmium
Xe - Xenon Br - Bromine
Ti - Titanium Cu - Copper (Cuprous)
Fe - Iron(Ferrum)
Si - silicon
Ir - Iridium Pt - Platinum
8. What are the
molecular formulae of the following compounds?
Hydrochloric acid – HCl
sulphuric acid – H2SO4
sodium chloride – NaCl
glucose – C6H12O6
methane – CH4
9. Under which
different types can the following changes be classified?
(a) Conversion of milk
into yoghurt – Chemical,
irreversible, slow.
(b) Bursting of a
cracker - Chemical,
irreversible, fast.
(c) Occurrence of an
earthquake – Physical, chemical,
irreversible, natural.
(d) Revolution of the
earth around the sun - Periodic,
slow, natural.
(e) Stretching of a
spring - Physical, reversible.
