National Maths and Science Quiz 2011 Contest 26

ROUND ONE

Q. The scale of a map is 1 cm to 10 km. Express the scale as a ratio. (M)

A. [ ]

Q. The scale on a map is given by a ratio of . If a road measures 10 km on the ground,

find its length on the map. (M)

A. 5 cm/ 0.05 m

Preamble: A soccer fan riding on a fast train moving at constant speed throws a ball vertically
upwards and keeps his hands up. (P)

Q. Where will the ball fall and why?

A. The ball will fall in his hands: the horizontal velocity of the ball is identical to that of the
fan and so there is no horizontal relative displacement between them

Q. What will be the trajectory of the ball as observed by someone on the ground?
A. Parabolic path with a horizontal velocity component in the same direction as the train

Q. Pure H2SO4 has a relatively high boiling point (338°C for 98% pure acid). Why? (C)
A. Strong Hydrogen bonds or strong intermolecular forces

Q. How many covalent bonds are present in a molecule of H2SO4? (C)

A. 8 covalent bonds

[ ]

Q. What name is given to the thick slimy layer that encloses the filament of Spirogyra? (B)
A. Mucilage

Q. What name is given to the colourless ovoid and protein-like bodies that occur in the chloroplast of
Spirogyra? (B)
A. Pyrenoid

Preamble: Solve for (M)

Q.
A. [ ]

Q.
A. [ ]

1
National Maths and Science Quiz 2011 Contest 26

Q. A two-input NAND gate is driven by the outputs of an OR and an AND gate. What is the output of
the NAND gate if all inputs of the OR and AND gates are 1? (P)
A. 0

Q. A two-input NAND gate is driven by the outputs of a NOT and an AND gate. What is the output
of the NAND gate if all inputs are 1 except one input of the AND gate which is 0? (P)
A. 1

Q. 2-Butanol is heated with iodine in the presence of aqueous NaOH. What is expected to be
observed? (C)
A. A yellowish crystalline compound (Iodoform – Triiodomethane CHI 3) of characteristic smell is
formed

Q. Name the product expected when 2-butanol is treated with acidified K2Cr2O7. (C)
A. 2-Butanone

Q. Decomposers have a food web of their own which is referred to as? (B)
A. Detritus food web

Q. The study of the dynamics of energy flow through ecological systems is known as? (B)
A. Ecological energetics

Preamble: List the members of the set (M)

Q.
A.

Q.
A.

Preamble: A dumbbell comprises two 5 kg masses at each end of a light 10 cm rod. (P)

Q. What is the moment of inertia of the dumbbell about an axis perpendicular to the rod and
passing through the centre of the rod?
A. 250kgcm2=0.025 kgm2
[ ]

Q. What is the moment of inertia about an axis perpendicular to the rod and passing through
one of the masses?
A. 500 kg cm2
[ ]

Q. Define half-life of a radioactive substance. (C & P)

A. It is the time taken for radioactivity of that substance to decay to half of its original value.

Q. Two experiments were set up, one in Ghana and the other in Iceland, to determine the half-life of a
radioactive element. How would the results compare? (C & P)

2
National Maths and Science Quiz 2011 Contest 26

A. The two half-lifes will be the same (within experimental limits) since temperature does not affect
radioactive decay

Q. Explain how blood in the veins is pushed back to the heart. (B)
A. The contraction of muscles near the veins pushes the blood back

Q. Explain how blood keeps flowing through the arteries. (B)

A. The beat of the heart supplies the pressure that keeps the blood moving

Preamble: Express the decimal number in standard form (M)

Q. 8,540,000
A.

Q. 0.00000793
A.

Q. What is the effective spring constant of two springs connected in parallel? (P)
A. Sum of the spring constants of the springs

Q. What is the effective spring constant of two identical springs connected in series? (P)
A. Half the spring constant of each

Q. How many elements are present in the section of the periodic table, normally labelled as the p-
block? (C)
A. 30

Q. There are two series of elements in the f-block of the periodic table. Name them. (C)
A. The Lanthanide Series (Lanthanoids) and The Actinide Series (Actinoids)

Q. What is polyploidy? (B)

A. Having more than two complete sets of chromosomes per cell

Q. What name is given to the crossing of different varieties of species? (B)

A. Hybridization

3
National Maths and Science Quiz 2011 Contest 26

ROUND TWO (Problem of the Day) (C)

You have been provided all the apparatus needed to prepare a column for column chromatograph to
separate two coloured compounds. Describe how the column will be set up.

Solution

Procedure

1. The glass column is washed thoroughly with detergent, rinsed and dried in the oven at 110-
120°C.
2. The column is clamped upright, on a retort stand.
3. A small plug of cotton or glass wool is pushed down to the bottom of the column.
4. The column is filled with petroleum ether (boiling range 60-80°C).
5. A suitable quantity of the adsorbent is weighed in a beaker.
6. A small volume of petroleum ether is added and the mixture stirred to give a slurry.
7. Using a funnel, and while stirring, the slurry is added, small quantities at a time to the column
whose tap is left open.
8. The column is gently tapped with the glass rod to prevent any air bubble being formed or
trapped.
9. When all the slurry has been added, there should be some solvent on top of the adsorbent.
10. The tap is now closed until the column is about to be used.

4
National Maths and Science Quiz 2011 Contest 26

ROUND THREE (True or False)

Q. The electric field of two equal charges has maximum magnitude at the centre of the line joining the
charges. (P)
A. False

Q. A moving point charge creates a magnetic field. (P)

A. True

Q. The maximum electric field that can be applied to an insulator without damage is known as the
dielectric strength of the insulator. (P)
A. True

Q. Insulators with high dielectric strength give larger capacitance compared to low dielectric strength
materials. (P)
A. False

Q. Leeches have distinct head and parapodia. (B)

A. False (no distinct head)

Q. Guinea worm belongs to the phylum Annelida. (B)

A. False (Nematoda)

Q. Spirogyra is capable of locomotion. (B)

A. False

Q. Spirogyra is both a protoctist and a green alga. (B)

A. True.

Q. , then (M)
A. False [ ]

Q. (M)
A. True

Q. (M)
A. False [ ]

Q. (M)
A. True

Q. Atoms of sulphur have smaller radius than phosphorus. (C)

A. True [atomic radius decreases from left to right]

Q. It is easier for hydrogen to lose an electron than lithium. (C)

A. False [ ]

Q. A gas that is acidic to litmus and decolourises acidified KMnO 4 solution could be SO2. (C)

5
National Maths and Science Quiz 2011 Contest 26

A. True

Q. A gas that is neutral to litmus and gives an explosion with a lighted splint is likely to be hydrogen.
(C)
A. True

6
National Maths and Science Quiz 2011 Contest 26

ROUND FOUR (Riddles)

Q. I was a French soldier, a naturalist, and an academic. I developed a particular interest in botany,
and later, published a three-volume work called Flora francaise. I am an early proponent of the idea
that evolution occurred and proceeded in accordance with natural laws. Today, I am mostly
remembered for the theory of inheritance of acquired characteristics. Who am I? (B)
A. Jean Lamarck

Q. I am so strong that I can change the shape of even big molecules. I am a relationship that involves
elements to the right of the Periodic Table. But that is not enough; I need the participation of the
lightest element in the Periodic Table. I relate better with liquids and solids and to a limited extent
with gases. I am responsible for the relatively high boiling point of water compared to its siblings.
Who am I? (C)
A. Hydrogen bonding

Q. I am electronic device. I am made with transistors and other electronic components. I usually have
two inputs and one output. A voltage at one of my inputs results in an output with opposite sign so
that input is called inverting. I can amplify a small voltage difference at my inputs to give a large
output voltage. How much amplification you get depends on what feedback resistors and other
components you connect to me. Who am I? (P)
A. Operational amplifier

Q. For a function, there are two of us, like a pilot and a co-pilot. I determine whether a function
makes sense or not. To be precise, I am a set. I consist of independent values of a variable. For the
function , I am the set of all values of . For any polynomial function, I am the set of real
numbers. Who am I? (M)
A. Domain (of a function)