write activity 14.3 of class 8 science ncert textbook and plz give me
Answers
Answer:
Explanation:
Activity 14.3
Take the tray from inside a discarded matchbox. Wrap an electric wire a few times around the tray. Place a small compass needle inside it. Now
connect one free end of the wire to the terminal of a battery. Leave the
other end free. Take another piece of wire and connect it to the other
terminal of the battery.
Fig 14.4 : Another tester
sufficiently and it does not glow. And why is the current in the circuit weak?
Well, though a material may conduct electricity, it may not conduct it as
easily as a metal. As a result, the circuit of the tester may be complete
and yet the current through it may be too weak to make the bulb glow. Can
we make another tester which can detect a weak current?
We can use another effect of an electric current to make another kind of tester. Do you recall that electric current
produces a magnetic effect? What happens to a compass needle kept nearby when current flows in a wire? Even if the current is small, the deflection of the magnetic needle can be seen. Can we make a tester using the magnetic effect of currents? Let us find out in Activity 14.3.
Join the free ends of two wires momentarily. The compass needle should show deflection. Your tester with two free ends of the wire is ready.
Now repeat Activity 14.2 using this tester. Do you find a deflection in the compass needle the moment you dip the free ends of the tester in lemon
juice? Take out the ends of the tester from the lemon juice, dip them in water and then wipe them dry. Repeat the activity with other liquids such as tap water, vegetable oil, milk, honey. (Remember to wash and wipe dry the ends of tester after testing each liquid). In each case observe whether the magnetic needle shows deflection or not.
HOPE IT HELPS
IN THIS ACTIVITY YOU HAVE TO FIND THAT THE NAME OF THIS ACTIVITY IS - MAKE A TESTER WITH USE OF MAGNETIC EFFECT
AIM- WE HAVE TO FIND THAT WHILE PUTTING MANY LIQUIDS THAT CONDUCT VERY SMALL AMOUNT OF CURRENT WHICH CAN BE DETECT BY USING MAGNETIC COMPASS.
MATERIALS REQUIRED - MAGNETIC COMPASS, BATTERY, WIRE AND LIQUIDS WE HAVE TO CHECK.
PROSEDURE - FIRST WE HAVE TO TAKE A MAGNETIC COMPASS AND ROLL WITH THE THE WIRE AND CONNECT TO THE BATTERY AND LET THE TWO WIRES FREE THEN AND PUT THE LIQUIDS THAT WE HAVE TO CHECK AND PUT WIRES IN LIQUIDS FIRST LIMITED LEMON JUICE BY WHICH WE CAN FIND THAT IT IS A GOOD CONDUCTOR AND WE HAVE TO TAKE VINEGAR THAT IS ALSO GOOD CONDUCTOR AND THEY SECOND THIRD ONE WE HAVE TO TAKE THE TAB WATER WHICH IS ALSO GOOD CONDUCTOR KNOW KM
