Ncert – class 8- science – Chapter 11: Chemical Effects of Electric Current 2 Welcome to your Ncert - class 8- science - Chapter 11: Chemical Effects of Electric Current 2 1. In charging a battery of motor-car, which of the following effect of electric current is used? Induction Magnetic Chemical Heating None 2. 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 (i) is correct (iv) is correct (ii) is correct (iii) is correct None 3. Of the following, the one that does not make use of chemical effect of electric current is : Electroplating Thermoelectric refrigerator Voltaic cells Electrotyping None 4. What happens when you join the free ends of the tester for more than a few minutes? All of the above Cells of the battery will drain quickly. There would be no conduction of electricity. The current will not be able to pass None 5. The process in which a layer of one metal is coated with another metal by electrolysis is called: Electropathy Electrorefining Electroplating Electrostatics None 6. Which of the following is not true about LED? There are two wires (called leads) attached to an LED. While connecting to a circuit, the longer lead of LED is always connected to the positive terminal of the battery. While connecting to a circuit, the shorter lead of LED is always connected to the positive terminal of the battery. LED can be used to detect weak current. None 7. Which of the following metals is used in electroplating to make objects appear shining? iron aluminium chromium copper None 8. Which one of the following scientists showed that if electrodes are immersed in water and a current was passed, bubbles of oxygen and hydrogen were produced? William Nicholson William Watson William Thomson William Harvey None 9. In charging a battery of motor car, which of the following effect of electric current is used? heating magnetic chemical induction None 10. An electric current can produce chemical effect only. magnetic effect only. heating effect only. chemical, heating, and magnetic effects. None 11. In electroplating of a silver spoon with gold, the gold plate is connected to: The negative terminal of the battery The positive terminal of the battery None of these Both positive and negative terminals of the battery None 12. The process of depositing a layer of gold on silver is known as: Electrolysis None of these Silver plating Electroplating None 13. Which of the following devices can be used to detect a weak current? Use of electric bulb in tester. BothUse of LED in tester. andA tester using magnetic effects of current. Use of LED in tester. A tester using magnetic effects of current. None 14. In electroplating of the silver spoon with gold, the silver spoon is cleaned with a dilute acid solution to remove the _________ from its surface. chloride layer silver layer gold layer oxide layer None 15. In LEDs, the longer lead is connected to ................ and the shorter lead is connected to ................... Positive terminal, Negative terminal Negative terminal, Positive terminal Positive terminal, Neutral terminal Negative terminal, Neutral terminal None Time's up Please Share This Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Leave a Reply Cancel replyCommentEnter your name or username to commentEnter your email address to commentEnter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
