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Chemical effects of electric current

Is it safe for the electrician to carry out electrical repairs outdoors during
heavy downpour? Explain.

05/11/2024

Science

8th

Tissues

Why are xylem and phloem called complex tissues? How are they different from one other?

05/11/2024

Science

9th

Chemical effects of electric current

A child staying in a coastal region tests the drinking water and also the
seawater with his tester. He finds that the compass needle deflects more
in the case of seawater. Can you explain the reason?

05/11/2024

Science

8th

Tissues

List the characteristics of cork. How are they formed? Mention their role.

05/11/2024

Science

9th

Chemical effects of electric current

In case of a fire, before the firemen use the water hoses, they shut off the
main electrical supply for the area. Explain why they do this.

05/11/2024

Science

8th

Chemical effects of electric current

Does pure water conduct electricity? If not, what can we do to make it
conducting?

05/11/2024

Science

8th

Chemical effects of electric current

A tester is used to check the conduction of electricity through two liquids,
labelled A and B. It is found that the bulb of the tester glows brightly for
liquid A while it glows very dimly for liquid B. You would conclude that
(i) liquid A is a better conductor than liquid B.
(ii) liquid B is a better conductor than liquid A.
(iii) both liquids are equally conducting.
(iv) conducting properties of liquid cannot be compared in this manner.

05/11/2024

Science

8th

Chemical effects of electric current

When the free ends of a tester are dipped into a solution, the magnetic
needle shows deflection. Can you explain the reason?

05/11/2024

Science

8th

Chemical effects of electric current

Fill in the blanks.
(a) Most liquids that conduct electricity are solutions of ,
______________ and ______________.
(b) The passage of an electric current through a solution causes
______________ effects.
(c) If you pass current through copper sulphate solution, copper gets
deposited on the plate connected to the terminal of the
battery.
(d) The process of depositing a layer of any desired metal on another
material by means of electricity is called .

05/11/2024

Science

8th

Sound

Lightning and thunder take place in the sky at the same time and at the
same distance from us. Lightning is seen earlier and thunder is heard
later. Can you explain why?

05/11/2024

Science

8th