The fluorescent tubes and neon sign bulbs glow because of ___________

The largest cell in human body is

The fig 8.39 shows how the speed of a marble changes as it rolls down an inclined plane A , travels on a flat horizontal surface and then on another inclined plane B Then the total time during which the marble is in motion is

If g and G stand fro acceleration due to gravity and gravitational constant respectively, then at the centre of the earth

Two particles of masses 1 g and 4 g have equal momentum.What is the ratio between their kinetic energies?

When ice melts there is a ............ in volume.

Events can be roughly divided into ono-metal and ..............

Classification helps us in exploring the .............. of life form.

Uneven heating of air over land and water bodies causes ............

Wheat, sorghum and rice provide us......................... .

What is a tissue?

How would you choose between two characteristics to be used for developing a hierarchy in classification?

Write one point of difference between infrasonic sound and ultrasound

Choose the odd one:
Mullets, bhetki, prawns, pearl spots.

(a) What is the 'Tyndall effect? Describe an activity to show that a true solution does not show the Tyndall effect.
(b) Which of the following will show the Tyndall effect? Give reason also:
(i) Milk      
(ii) Salt solution
(iii) Sugar solution  
(iv) Starch solution
(v) Air      
(vi) Tincture iodine.

Give an account of the 'mole concept'

Atomic mass of an element is the sum of no. of protons and neutrons which are whole numbers.How do you account for the fractional atomic masses of elements?

Will advanced organisms be the same as complex organisms? Why?

Classify the following as scalar and vector quantities:
Temperature,mass,volume,speed,displacement,time,distance,velocity ,electric charge,acceleration,force,momentum,density,work,weight,energy

A hockey ball of mass 200 g travelling at 10 m s^–1 is struck by a hockey stick so as to return it along its original path with a velocity at 5 m s^–1. Calculate the magnitude of change of momentum occurred in the motion of the hockey ball by the force applied by the hockey stick.

Gravitational force acts on all objects in proportion to their masses. Why then, a heavy object does not fall faster than a light object?

State law of conservation of energy.What is the work done when an object moves on a circular path?

A ship sends out ultrasound that returns from the seabed and is detected after 4s.If the speed of ultrasound through sea water is 1550 m/s, find the distance of the seabed from the ship.

Name two internal parasites and their target organs.

Write would you observe when
(i) A saturated solution of potassium chloride prepared at 608\(°\)C is allowed to cool at room temperature.
(ii) An aqueous solution of sugar is heated to dryness.
(iii) A mixture of iron filings and sulphur powder is heated strongly.

(a) Name a green house gas with molar mass 14g/mol and is known to extinguish fire.
(b) Name the elements present in this gas and write their valency
(c) Calculate the number of moles in 360 g of this gas sample
(d) Calculate the number of molecules in 88 g of this gas sample
(Given atomic mass of C =12u, O = 16u, No=6.022 x 10²³ per mole)

What are phanerogams? How are they classified? Give example.

From a rifle of mass 4 kg, a bullet of mass 5 g is fired with an initial velocity of 35 \(m s^{-1}\) Calculate the initial recoil velocity of the rifle.

Differentiate between 'g' and 'G' in a tabular form.

Define the term 'tone'.A person id listening to a sound of 500Hz sitting at a distance of 450m from the source of the sound.What is the time interval between successive compression reaching his ears from the source?

Mention the management practices that are common between dairy and poultry farming.

(a) Convert 359 K to Celsius scale
(b) What is the value of boiling point of water on Kelvin scale of temperature?

What is the advantage of using scientific names instead of common or popular names?

A stone is dropped from the adge ofg the roof, find
(i) How long does it take to fall 4.9 m?
(ii) How fast does it move at the end of that fall?
(iii) How fast does it move at the end of 7.9 metres?
(iv) What is its acceleration after 1 s and after 2s?