CBSE Class 8   CBSE Class 8 Science

Distinguish between the following. Cell and Battery ,An Open Switch and A Close Switch (1)
With the help of an activity explain the making of an electromagnet (1)
The bulb in the circuit shown in figure below does not glow. Can you identify the problem? Make necessary changes in the circuit to make the bulb glow (1)
In the circuit shown below (1)
Describe a simple experiment to show that the bulb lights up when an electric circuit is complete and vice-versa (1)
How does the magnetic effect of electric current help in the working of an electric bell? Explain with the help of a diagram (1)
Paheli took a wire of length 10 cm. Boojho took a wire of 5 cm of the same material and thickness (1)
When the current is switched on through a wire, a compass needle kept nearby gets deflected from its north-south position. Explain (1)
How do short circuits occur? (1)
Write four uses of electromagnets (1)
On what factors does the strength of an electromagnet depend? (1)
On what factors does the heat produced in a wire depend? (1)
What are electric fuses? Why are they important? (1)
Will the compass needle show deflection when the switch in the circuit shown by figure given below is closed? (1)
Name any two effects of electric current (1)
The figure below shows four cells fixed on a board. Draw lines to indicate how you will connect their terminals with wires to make a battery of four cells (1)
Draw the circuit diagram to represent the circuit shown below (1)
Draw in your notebook the symbols to represent the following components of electrical (1)
Boojho made an electromagnet by winding 50 turns of wire over an iron screw (1)
Why do we cover plug pin holes which are within the reach of children with cellotape or a plastic cover when not in use? (1)
Name two electric devices for each where heating effect of current is used and magnetic effect of current is used (1)
Can we use the same fuse in a geyser and a television set? Explain (1)
With the help of Newton’s disc, prove that seven colours of the rainbow can be recombined and produce white light (1)
Explain the reflection of light on white paper screen with the help of an activity (1)
Distinguish between the following. Real image and Virtual image ,Convergent beam and Divergent beam (1)
You are given three mirrors of different types. How will you identify each one of them? (1)
What is rectilinear propagation of light? How will you prove it? (1)
What is regular and irregular reflection? (1)
Suppose we wish to obtain the real image of a distant tree (1)
It was observed that when the distance between an object and a lens decreases (1)