Solutions of practice worksheet 2 (class 6)

Solutions of practice worksheet 2 (class 6)

Q 1:- Short answer questions:          (2x7=14 marks)

i)   Can you think of creating a shape that would give a circular shadow if held in one way and a rectangular shadow if held in another way?

Ans. Yes, Cylindrical object kept vertically will give rectangular shadow while Cylindrical object kept horizontally will give circular shadow .

ii) Discuss in brief two ways of water harvesting.

Ans. Increasing the availability of water is to collect rainwater and store it for later use. Collecting rainwater in this way is called rainwater harvesting.

    The two techniques of rainwater harvesting are:

1.     Rooftop rainwater harvesting: In this system the rainwater is collected from the rooftop to a storage tank, through pipes. This water may contain soil from the roof and need filtering before it is used. Instead of collecting rainwater in the tank, the pipes can go directly into a pit in the ground. This then seeps into the soil to recharge or refill the ground water. 

2. Another option is to allow water to go into the ground directly from the roadside drains that collect rainwater.

 

iii) What name is given to the electric circuit:

a. in which there is a gap?

Ans. Open circuit

 

b. in which there is no gap?

Ans. Closed circuit 

    iv) What is the proper way of storing bar magnets when not in use?

    Ans. To keep them safe, bar magnets should be kept in pairs with their unlike poles                 on the same side.

            They must be separated by a piece of wood while two pieces of soft iron should              be placed across their ends.

     v) Write two characteristics of images formed by each:

a.  images formed by a plane mirror

Ans. Virtual and Erect

b.  images formed in a pinhole camera.

Ans. Real and inverted

vi) Write any two important properties of air.

Ans. Important properties of air (any two)

•      Colourless, tasteless and Odourless

•      Has mass

•      Occupies space

•      Exert pressure

•      Dissolves in water

vii) When Harsh flashed a torch on a mirror at an angle, he observed that it bounced off as depicted below:

                                               

a)       Name the property of light shown in the diagram.

Ans. Reflection of light

b)      What is the impression of an object seen in a mirror called?

Ans. Image

c)  Will a transparent surface like glass instead of mirror shows the above phenomenon? Why?

Ans. No because transparent surface like glass will allow light to pass through it instead of being bounced back (reflection).

Q.2. Give reasons why:         (2x3=6 marks)

a) Handle of electricians screw driver made of plastics.

Ans. Plastic or rubber is an insulator which does not allow electric current to pass through it. The handles of the tools like screwdrivers and pliers used by electricians for repair have covering of plastic or rubber so that electric current may not pass through these tools to the body of the electrician to harm him.

b) Deep sea divers carry oxygen cylinders with them.

Ans. There is no free oxygen in the sea water as it is available in air and they cannot breathe through dissolved oxygen present in water. In absence of oxygen, they could die. So, Sea divers carry oxygen gas cylinders along with them 

c) Water is a renewable resource even then we should conserve this.

Ans. Water is a renewable source because it gets replenished again into useable form but if this renewable source is used excessively without giving it a chance to regenerate into useable form, then it might get exhausted.

In short, if rate of consumption is higher than rate of regeneration/replenishing, then useable form of water will exhaust one day and conditions like drought will generate.