When the objects are at rest, the interlocking of irregularities in the two surfaces of the objects is higher than that of when objects are moving. When objects are moving, there is less interaction between their surfaces. That's why sliding friction is less than static friction. https://www.tiwariaRead more
When the objects are at rest, the interlocking of irregularities in the two surfaces of the objects is higher than that of when objects are moving. When objects are moving, there is less interaction between their surfaces. That’s why sliding friction is less than static friction.
Impure Copper plate should be connected to positive terminal. Pure copper plate should be connected to negative terminal of electrode as copper ions are positively charged and will attract to negative electrode terminal. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
Impure Copper plate should be connected to positive terminal. Pure copper plate should be connected to negative terminal of electrode as copper ions are positively charged and will attract to negative electrode terminal.
Cold drink cans are tin plated. Artificial Jewellery items are silver or gold-plated. Car bumpers and cycle handles are chromium plated. Metal doors, door handles are zinc plated. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
Cold drink cans are tin plated. Artificial Jewellery items are silver or gold-plated. Car bumpers and cycle handles are chromium plated. Metal doors, door handles are zinc plated.
Air in our surroundings contains gasses, suspended dust particles and pollutants. These particles gets dissolved in rain water and make it good conducting medium of electricity. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
Air in our surroundings contains gasses, suspended dust particles and pollutants. These particles gets dissolved in rain water and make it good conducting medium of electricity.
No it is very risky and unsafe to carry out electric repairs outdoors during heavy downpour. Water (when impure) is a good conductor of electricity and there are chances of getting electric shock. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
No it is very risky and unsafe to carry out electric repairs outdoors during heavy downpour. Water (when impure) is a good conductor of electricity and there are chances of getting electric shock.
Drinking water is chemically treated and purified by removing various impurities and salts from it. While the sea water contains lots of mineral salts. Therefore, sea water produce more ions (more electric charges) as compared to drinking water and the child sees more deflection in magnetic needle iRead more
Drinking water is chemically treated and purified by removing various impurities and salts from it. While the sea water contains lots of mineral salts. Therefore, sea water produce more ions (more electric charges) as compared to drinking water and the child sees more deflection in magnetic needle in case of sea water.
The water usually contain salts and is a good conductor of electricity. To save themselves and others from electric shock and to avoid any short circuit, firemen shut off the main electrical supply for the area. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
The water usually contain salts and is a good conductor of electricity. To save themselves and others from electric shock and to avoid any short circuit, firemen shut off the main electrical supply for the area.
Pure or distilled water does not contain salts. Therefore it is a poor conductor of electricity. We can add impurities like salt, lemon juice, vinegar etc. to make it conducting. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
Pure or distilled water does not contain salts. Therefore it is a poor conductor of electricity. We can add impurities like salt, lemon juice, vinegar etc. to make it conducting.
The deflection of magnetic needle indicates electric current is flowing through the wire. It means the liquid or the solution is a good conductor of electricity. When the free ends of a tester are dipped into a solution, electric circuit is completed and an electric current passes through the solutiRead more
The deflection of magnetic needle indicates electric current is flowing through the wire. It means the liquid or the solution is a good conductor of electricity. When the free ends of a tester are dipped into a solution, electric circuit is completed and an electric current passes through the solution.
Explain why the sliding friction is less than the static friction.
When the objects are at rest, the interlocking of irregularities in the two surfaces of the objects is higher than that of when objects are moving. When objects are moving, there is less interaction between their surfaces. That's why sliding friction is less than static friction. https://www.tiwariaRead more
When the objects are at rest, the interlocking of irregularities in the two surfaces of the objects is higher than that of when objects are moving. When objects are moving, there is less interaction between their surfaces. That’s why sliding friction is less than static friction.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-12/
See lessThe process that you saw in Activity 14.7 is used for purification of copper. A thin plate of pure copper and a thick rod of impure copper are used as electrodes. Copper from impure rod is sought to be transferred to the thin copper plate. Which electrode should be attached to the positive terminal of battery and why?
Impure Copper plate should be connected to positive terminal. Pure copper plate should be connected to negative terminal of electrode as copper ions are positively charged and will attract to negative electrode terminal. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
Impure Copper plate should be connected to positive terminal. Pure copper plate should be connected to negative terminal of electrode as copper ions are positively charged and will attract to negative electrode terminal.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
See lessPrepare a list of objects around you that are electroplated.
Cold drink cans are tin plated. Artificial Jewellery items are silver or gold-plated. Car bumpers and cycle handles are chromium plated. Metal doors, door handles are zinc plated. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
Cold drink cans are tin plated. Artificial Jewellery items are silver or gold-plated. Car bumpers and cycle handles are chromium plated. Metal doors, door handles are zinc plated.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
See lessPaheli had heard that rainwater is as good as distilled water. So she collected some rainwater in a clean glass tumbler and tested it using a tester. To her surprise she found that the compass needle showed deflection. What could be the reasons?
Air in our surroundings contains gasses, suspended dust particles and pollutants. These particles gets dissolved in rain water and make it good conducting medium of electricity. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
Air in our surroundings contains gasses, suspended dust particles and pollutants. These particles gets dissolved in rain water and make it good conducting medium of electricity.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
See lessIs it safe for the electrician to carry out electrical repairs outdoors during heavy downpour? Explain.
No it is very risky and unsafe to carry out electric repairs outdoors during heavy downpour. Water (when impure) is a good conductor of electricity and there are chances of getting electric shock. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
No it is very risky and unsafe to carry out electric repairs outdoors during heavy downpour. Water (when impure) is a good conductor of electricity and there are chances of getting electric shock.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
See lessA 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?
Drinking water is chemically treated and purified by removing various impurities and salts from it. While the sea water contains lots of mineral salts. Therefore, sea water produce more ions (more electric charges) as compared to drinking water and the child sees more deflection in magnetic needle iRead more
Drinking water is chemically treated and purified by removing various impurities and salts from it. While the sea water contains lots of mineral salts. Therefore, sea water produce more ions (more electric charges) as compared to drinking water and the child sees more deflection in magnetic needle in case of sea water.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
See lessIn 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.
The water usually contain salts and is a good conductor of electricity. To save themselves and others from electric shock and to avoid any short circuit, firemen shut off the main electrical supply for the area. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
The water usually contain salts and is a good conductor of electricity. To save themselves and others from electric shock and to avoid any short circuit, firemen shut off the main electrical supply for the area.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
See lessDoes pure water conduct electricity? If not, what can we do to make it conducting?
Pure or distilled water does not contain salts. Therefore it is a poor conductor of electricity. We can add impurities like salt, lemon juice, vinegar etc. to make it conducting. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
Pure or distilled water does not contain salts. Therefore it is a poor conductor of electricity. We can add impurities like salt, lemon juice, vinegar etc. to make it conducting.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
See lessA 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. https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
(i) Liquid A is a better conductor than liquid B.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
See lessWhen the free ends of a tester are dipped into a solution, the magnetic needle shows deflection. Can you explain the reason?
The deflection of magnetic needle indicates electric current is flowing through the wire. It means the liquid or the solution is a good conductor of electricity. When the free ends of a tester are dipped into a solution, electric circuit is completed and an electric current passes through the solutiRead more
The deflection of magnetic needle indicates electric current is flowing through the wire. It means the liquid or the solution is a good conductor of electricity. When the free ends of a tester are dipped into a solution, electric circuit is completed and an electric current passes through the solution.
https://www.tiwariacademy.com/ncert-solutions/class-8/science/chapter-14/
See less