- Define the SI unit of work.
- What kind of energy transformation takes place when a body is
dropped from some height?
- Name two acids that are present in acid rain.
- Name the disease caused by water contaminated by mercury.
a) How many atoms of sodium are there in a sample measuring 2
× 102 moles?
b) Write the formula of nitrate of
B2+ and aluminium salt of X-.
- Draw a sketch of Bohr’s model of the atom with five
electrons in the “M” shell. Identify the element and
also write its electronic configuration.
- The diagram given here shows characteristic features of two
subkingdoms. Identify the subkingdoms, and write any two
differences between them.
- Describe the class of warm-blooded animals in which the teeth
- State Archimedes’ principle.
- The relative density of iron is 7.7. what is the density in the SI system.
- What are ultrasonic waves? Name three animals that can hear
- Describe any four methods of weathering of soil.
- What are the causes of water pollution?
a) Calculate the molecular mass of
C = 12, H = 1, O = 16, P = 31)
b) Carbon and oxygen combine in
the ratio of 3:8 by mass to form carbon dioxide. What
mass of oxygen gas would be required to react completely with 36 g
of carbon? (2)
Calculate the mass of:
(i) 1.5 moles of oxygen molecules
(ii) 1.5 moles of oxygen atoms
(iii) 3.011 × 1023
oxygen atoms (atomic mass: O = 16)
- Write any three differences between chordates and
- Describe any three infectious agents.
- Describe the mode of transmission of diseases through air,
water and animals, with examples.
- How can we prevent infectious diseases?
- Derive the relation between the SI unit and the CGS unit for
- A boy standing in front of a cliff claps and hears an echo
at the end of 3 s. If the speed of sound in air is 342 m/s, find
the distance between the cliff and the boy.
Observe the graphical representation of a wave given here
and answer the questions that follow. The quantity plotted along
the X-axis is time, and against the Y-axis is displacement of the
vibrating particle in the wave.
a) What is the nature of the wave?
b) What is the wavelength of the wave?
c) What is the quantity denoted by the letter "B" in the
a) Explain the term isotope with an example.
b) Of the three fundamental
particles of an atom, which elementary particle(s) influences the
following properties of an element? Give suitable reasons for your
chemical identity of an atom (whether it is an atom of hydrogen or
mass of an
c) What were the
conclusions of Rutherford's alpha particle scattering experiment?
a) What sub-atomic particles make up the nucleus? What is their
mass and charge?
b) What is the importance of isotopes in medicine?
c) In Rutherford’s scattering experiment, very few of the
α-particles that hit the gold foil are deflected back. What
(a) What is the work done in increasing the velocity of a
body of mass 2 kg from 4 m/s to 8 m/s?
(b) If the velocity of a
body is doubled, then what is the percentage increase in its
Name the kind of energy transformation that takes place in the
a) Electric heater
d) Electric cell
Describe the following processes:
Formation of ozone layer
Sketch a diagrammatic representation of the
nitrogen cycle, and explain how nitrogen is replenished in the
Among cat, dog, lion and wolf, which animals belong to the
a. Dog, lion
b. Cat, lion
c. Cat, dog
d. Dog, wolf
What type of seed is shown here?
Here is an egg-laying animal. Identify the
class to which it belongs.
Organisms of which phylum show the notochord only at
some stages during their lives?
Identify the feature in which these two animals are
a. Mammary glands
b. Urinary bladder
d. Four-chambered heart
Subhash cut a fresh water plant into small pieces, and he
observed that each of these fragments grew into a new plant.
Identify the plant.
A cuboidal block of dimensions 10 cm × 6 cm × 4
cm is placed on a surface. It exerts maximum pressure when the side
with the dimensions ____ is in contact with the surface.
a. 10 cm × 4 cm
b. 10 cm × 6 cm
c. 6 cm × 4 cm
d. Any dimension
The SI unit for pressure is ___.
A balloon filled with air is immersed forcibly and gradually
into a water trough. The balloon experiences maximum upthrust when
it is immersed:
a. Up to one-fourth of its volume
b. Up to half of its volume in
c. Up to three-fourths of
its volume in water
d. Completely in water
The density of gold is 19.3 g/cm3. Its relative
density is ____.
The purity of gold in an ornament can be found, without
destroying it, by using ____.
a. The law of conservation of
b. The principle of moments
d. Bernoulli's principle
The relative density of silver is 10.8. Its density is:
a. 108 kg/m3
b. 1.08 g/m3
c. 10.8 g/m3
A man standing between two parallel cliffs fires a gun and
hears two successive echoes at the end of 4 s and 6 s. The distance
between the cliffs is ___m.
(Speed of sound in air is 330 m/s.)
a. 1600 m
b. 1650 cm
c. 1650 m
d. 1590 m
The frequency of a tuning fork is 256 Hz.
The number of vibrations made by the fork in 10 s is _____.
40. In which of the following does sound
d. Car tyre
The Galton whistle, also called a dog
whistle, produces sounds in the range:
a. Below 20
b. 20 Hz to 20
d. 10 Hz to 20