Page 58 - Innovator's Science-8

4. Heat produced in a heating element on passing current through it depends on.
a. Nature of the material

b. Colour of the element 4. a b c d
c. Thickness of the wires of the element
d. Length of the wire of the element

B. Fill in the blanks. Observational Skills
1. Nichrome offers more ____________ to the flow of current compared to copper.

2. Energy loss during ____________ of electric current is also a problem related to the heating effect
of electric current.
3. Some of the electricity is used up in heating the fliment of the bulb, the reduce the ____________
of these bulbs.
4. The region around a magnet where its magnetic effect can be felt is said to have a ____________.

C. State whether the given statements are True (T) or False (F). Problem Solving Skills
1. Electromagnets do not have poles like the North pole and South pole of a bar magnet.

2. Pure water can be used as an electrolyte in a voltaic cell.
3. An electric heater is an example of the heating effect of electric current.
4. A hair dryer is an example of the magnetic effects of electric current.

D. Short answer type questions. Decision-making Skills
1. What is an electrolytes?

2. What is electrode?
3. Define magnetic field.
4. Name there types of portable sources of electricity.

E. Long answer type questions. Critical Thinking Skills
1. What variables increase or decrease the magnetic effects of electric current?
2. Are electromagnets also used in real life for lifting objects?

3. Explain how the discovery of the voltaic cell was made?
4. Explain the structure of a dry cell.

Project Ideas Exploration

1. Make a project diary to show that the electromagnets have two poles like a bar magnet.
2. Using two drawing pins, a safety pin, and a cardboard piece, make a switch.

Life Skills Inference

• Fuse wire is connected in series with the live wire. Why does its temperature rise much faster than
the connec ng copper wires?

Enhance your Life Skills Mental Development
1. Is it possible to make temporary magnets? How can these be made?

2. How do we know if a cell or a ba ery is dead? Can all cells and ba eries be recharged?
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Science-8