NAVODAYA VIDYALAYA SAMITI
LUCKNOW REGION PWT- 3
(SET-1)2020-21
CLASS-X SUBJECT - SCIENCE
M.M - 50 TIME ALLOTED 2.00 HR
SECTION A PHYSICS (17 Marks)
1. Linear magnification
produced by a concave lens is always 1MARK
a)
Less than 1
b)
More than 1
c)
Equal to 1
d)
More than 1 or less than 1
2.
The focal lengths of
four convex lenses P, Q , R and S are 20 cm, 15 cm, 5 cm and 10 cm respectively. The lens having greatest power is 1 MARK
a)
P
b)
Q
c)
R
d)
S
3. The magnification produced by a plane mirror is +1. What does this mean? 1 MARK
(i) image is real
(ii) image is virtual
(iii) image is erect
(iv) image is inverted
(v) image is of same size as that of object
Choose the correct option
(a) (i),(iii), (iv)
(b) (i),(iv), (v)
(c) (i),(iii),(v)
(d) (ii),(iii) ,(v)
4. The refractive indices
of four media A, B, C and D are given in the following table:
|
MEDIUM |
A |
B |
C |
D |
|
REFRACTIVE INDEX |
1.33 |
1.50 |
1.52 |
2.40 |
If light, travels from one medium to another, in which case the
change in speed will be
(i)
minimum
(ii)
maximum ? 1 MARK
5. Redraw the given diagram
and show the path of the refracted ray: 1 MARK
6.
How should a ray of
light be incident on a rectangular glass slab so that it comes out from the opposite side of the slab
without being displaced? 1 MARK
7.
A convex mirror used for rear view on an automobile has a radius of curvature
of 3 m. If a bus is located
at 5 m from this mirror, find magnification? 2 MARKS
8. In an experiment with a rectangular
glass slab, a student observed that a ray of light incident at an angle of 55°
with the normal on one face of the slab, after refraction strikes the opposite
face of the slab before emerging out into air making an angle of 40° with the
normal. Draw a labelled diagram to show the path of this ray. What value would
you assign to the angle of refraction and angle of emergence? 2 MARKS
9.
The speed of light in
air is m/s. In the medium X its speed is m/s and in medium Y the speed of light is m/s. Calculate refractive index of medium Y
with respect to medium X. 2 MARKS
10. An object is placed at the following
distances from a convex lens of focal length 10 cm
a)
8 cm
b)
15 cm
c)
20 cm
d)
25 cm
Which
position of object will produce?
a)
A diminished real image?
b)
A magnified real image?
c)
A magnified virtual image?
d)
An image of the same size as the object? 2 MARKS
11. An object
placed 50 cm from a lens produces a virtual image at a distance of 10 cm in
front of the lens. Draw a diagram to show the formation of image. Calculate the
focal length of the lens and magnification produced. 3 MARKS
SECTION-B CHEMISTRY (17 Marks)
1. Identify the unsaturated compounds from the following 1Mark
(i) Propane (ii) Propene (iii) Propyne (iv) Chloropropane
a) (i) and (ii)
(b) (ii) and (iv)
(c) (iii) and (iv)
(d) (ii) and (iii)
2. Which of the following statements is/are usually correct for carbon compounds? 1MARK
(i) These are good conductors of electricity
(ii) These are poor conductors of electricity
(iii) These have strong forces of attraction between their molecules
(iv) These do not have strong forces of attraction between their molecules
a) (i) and (iii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (ii) and (iv)
(a) Alkynes
(b) Alkenes
(c) Alkanes
(d) Cyclo alkanes
a. Phosphorus
b. Sulphur
c. Carbon
d. Tin
5. Subsequent members of homologous series differ by how many atomic mass units?1 MARK
a.14
b.16
c.24
d.28
6. The H-C-H bond angle in methane is approximately……... degree. 1MARK
a.1050
b.107.50
c. 109.50
d.1200
Ans- c
7.Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same? 1MARK
(i) Good thermal conductivity
(ii) Good electrical conductivity
(iii) Ductility
iv) High melting point
Choose correct option-
(a) (i) and (ii)
(b) (i) and (iii)
(c) (ii) and (iii)
(d) (i) and (iv)8. The composition of aqua regiais 1MARK
(a) Dil.HCl : Conc. HNO3 3: 1
(b) Conc.HCl : Dil. HNO3 3 : 1
(c) Conc.HCl : Conc.HNO3 3 : 1
(d) Dil.HCl : Dil.HNO3 3: 1
9. Two elements A and B has 6 and 7 electrons in valance shell respectively. What will be the nature of bond formed between A and B? 1 MARK
a. Ionic
b. Covalent
c. Both of these
d. None of these
10. According to Mendeleev's Periodic law, the elements were arranged Periodic table according to - 1 MARK
a. Increasing atomic number
b. decreasing atomic number
c. Increasing atomic masses
d. decreasing atomic masses
11. What is homologous series? Which is the first member of alkene homologous series? 2 MARKS
12. Explain Dobereiner law of triad with example. 2 MARKS
13. a. Why did Mendeleev leave gaps in his periodic table. 1 MARK
b. How many groups and periods were there in Mendeleev’s Periodic table? 1 MARK
c. What is catenation? 1 MARK
SECTION C (BIOLOGY) (16 MARKS)
1. In evolutionary terms we have more in common with, 1 MARK
a. A Chinese boy
b. A chimpanzee
c. A spider
d. A bacterium
2. Which of the following are environmental friendly practices 1 MARK
a. Carrying cloth bags to put purchases in while shopping
b. Switching off unnecessary lights and fans
c. Walking to school instead of getting your mother to drop you on her scooter
d. All the above
3. An example of homologous organ is 1 MARK
a. Our arms and dogs forelegs
b. Our teeth and elephants tusk
c. Potato and runners of grass
d. All of these
4. Which of the following groups contains only Biodegradable items? 1 MARK
a. Grass, flower and leather
b. Grass, wood and Plastic
c. Fruit peels, Cake and lime Juice.
d. Cake, wood and grass
5. Name the branch of Science that deals with heredity and variations? 1 MARK
6. Name the Genetic material that is responsible for
inheritance of traits? 1 MARK
7. All variants in a species do not have equal chances
of survival, why? 2 MARK
8. Bacteria and fungi are called decomposers, why? 2 MARK
9. Explain the terms analogous and homologous organs with example? 3 MARK
10.
The depletion of Ozone layer is a cause of concern,
why? 3 MARK
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