ASSET 8.2 31-40

Sujata wants to make an electromagnet. Shown below are three arrangements that she has made with a battery, a wire and a cylinder. Which of these will work as an electromagnet?

• Only 1

• Only 3

• Only 1 and 2

• all - 1, 2 and 3

What is the normal AC voltage found in Indian homes?

• 110 V

• 200 V

• 220 V

• 440 V

For an average sized door, which of the following is closest to 1 metre?

• Thickness

• Width

• height

• surface area

At home, there are a number of appliances that convert electricity into one or more different forms of energy. An electric fan converts electricity into___________.

• Sound energy only

• sound and heat energy

• mechanical energy, sound energy, and heat energy

• mechanical energy, sound energy, heat energy, and chemical energy

A chemist working at a steel company is conducting research on a new alloy. Why is it important for her to keep accurate notes about her research?

• Accurate notes are necessary only when a researcher works for a company.

• Accurate notes are necessary to get the results she expects in an experiment.

• . Accurate notes will help to make sure that nobody can use the same methods that she did.

• Accurate notes will help her and other scientists to repeat the experiments and verify the results.

Which among the following would happen first if suddenly ice became denser than water?

• a lot of snow will melt in the polar regions   

• Marine life will be severely affected in cold regions

• . ice skating would become impossible

• water vapour content in air would decrease

What would happen if the axis of the earth were NOT tilted with reference to the plane of its revolution as shown in the second figure below?

• There would be no difference at all.

• The sun would rise in the west and set in the east.

• In any place, the weather will be more uniform throughout the year.

• At any time, the weather will be almost the same throughout the world.

A ball is thrown at a reflecting surface (mirror) as shown. A video camera is placed in line with the reflected path of the ball. What will the video camera record?

• A ball moving towards the camera, initially faster and then slower.

• A ball moving towards the camera, initially slower and then faster.

• A ball moving in a V shaped path, initially faster and then slower.

• A ball moving in a V shaped path, initially slower and then faster.

Observe the food web shown here. Which list contains all the CONSUMERS in this food web?

• Grasses, shrubs

• Grasses, shrubs, grasshoppers, mice, rabbits

• Hawks, foxes

• Grasshoppers, mice, rabbits, birds, hawks, foxes

You know that unlike magnetic poles attract - the south pole of one magnet is attracted to the north pole of another magnet within its magnetic field.

A magnetic compass responds to the earth's magnetic field and comes to rest in the North-South orientation with the North pole of the compass pointing to the Earth's geographic North. What does this imply?

• The earth's magnetic South pole is near its geographic North pole

• The earth's magnetic North pole is near its geographic North pole.

• The earth's magnetic poles are perpendicular to its geographic poles.

• The earth's magnetic poles lie at the core of the earth, which is a mass of molten iron.