This quiz works best with JavaScript enabled. Home > Cbse > Class 7 > Science > Electric Current And Its Effects > Class 7 Science Chapter 10 Electric Current And Its Effects – Quiz 16 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 7 Science Chapter 10 Electric Current And Its Effects Quiz 16 (30 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. The force exerted on a current carrying wire placed in a magnetic field is 0 when angle between the wire and the direction of magnetic field is: A) 90$^\circ$. B) 60$^\circ$. C) 180$^\circ$. D) 30$^\circ$. Show Answer Correct Answer: C) 180$^\circ$. 2. The more rolls of wire on iron screw, lesser pins will attract A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 3. Which are not the effect of an electric current? A) Electrical effect. B) Magnetic effect. C) Heating effect. D) Lightning effect. Show Answer Correct Answer: A) Electrical effect. 4. The colour of insulation of earth wire is: A) Red. B) White. C) Green. D) White. Show Answer Correct Answer: C) Green. 5. In an incandescent bulb, electric current passes through a very thin wire made of a special material. It is A) Alloy. B) Tungsten. C) Brass. D) Plastic. Show Answer Correct Answer: B) Tungsten. 6. Which of the devices use a battery? A) Torch. B) Transistor. C) TV Remote. D) All of these. Show Answer Correct Answer: D) All of these. 7. When the switch is on the circuit from the positive to negative terminal is complete A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 8. Who discovered bulb? A) Ohm. B) Flemming. C) Thomas Edison. D) Michael Faraday. Show Answer Correct Answer: C) Thomas Edison. 9. What glows even when a weak electric current passes through it? A) Tube light. B) CFL. C) LED. D) Bulb. Show Answer Correct Answer: C) LED. 10. What is the density of a piece of floating wood? A) 7.2 g / cm3. B) 1.0 g / cm3. C) 0.5 g / cm3. D) 100 g / cm3. Show Answer Correct Answer: C) 0.5 g / cm3. 11. A fuse wire is a wire of- A) High resistivity and low melting point. B) High resistivity and high melting point. C) Low resistivity and low melting point. D) Low resistivity and high melting point. Show Answer Correct Answer: B) High resistivity and high melting point. 12. The presence of ..... in leaves indicates the occurance of photosynthesis. A) Proteins. B) Starch. C) Fats. D) Oxygen. Show Answer Correct Answer: B) Starch. 13. What is the cause of the magnetic field around a current-carrying conductor? A) Magnetic charges. B) Gravitational force. C) Electric field. D) Flow of electrons. Show Answer Correct Answer: D) Flow of electrons. 14. Which of the following produces most heat? A) Long and thick wire. B) Long and thin wire. C) Short and thick wire. D) Short and thin wire. Show Answer Correct Answer: C) Short and thick wire. 15. Properties of chromium include: A) Shiny appearance. B) Does not corrode. C) Resists scratches. D) All of these. Show Answer Correct Answer: D) All of these. 16. A vertical wire carrying a current in the upward direction is placed in a horizontal magnetic field directed towards north. The wire will experience a force directed towards A) West. B) East. C) South. D) North. Show Answer Correct Answer: A) West. 17. The process of making magnet substance into a magnet is known as A) Magnetization. B) Magnet. C) All the above. D) None of the above. Show Answer Correct Answer: A) Magnetization. 18. Without the Gulf Stream, the southeastern United States and Europe would be ..... A) Warmer. B) Cooler. C) All the above. D) None of the above. Show Answer Correct Answer: B) Cooler. 19. Which of the following is the example of magnetic effect of electric current A) Electric Bell. B) Crane. C) All of these. D) None Of these. Show Answer Correct Answer: C) All of these. 20. A battery is the term used for a group of: A) Voltages. B) Negative electrodes. C) Positive electrodes. D) Cells. Show Answer Correct Answer: D) Cells. 21. The D.C. generator is based on the principle of: A) Electrostatic induction. B) Electromagnetic induction. C) Electrochemical induction. D) None of these. Show Answer Correct Answer: B) Electromagnetic induction. 22. The electrical charge created by rubbing two surfaces together is called: A) Photo-voltaic electricity. B) Piezo-electric crystal electricity. C) Moving electricity. D) Static electricity. Show Answer Correct Answer: D) Static electricity. 23. In a Wheatstone bridge if the battery and galvanometer are interchanged then the deflection in galvanometer will A) Change in previous direction. B) Not change. C) Change in opposite direction. D) None of these. Show Answer Correct Answer: B) Not change. 24. Iron used in bridges and automobiles are coated with A) Tin. B) Chromium. C) Zinc. D) Copper. Show Answer Correct Answer: C) Zinc. 25. If we keep a compass inside a cardboard with cell and switch attached, it shows magnetic effect of current. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 26. How can corrosion be prevented in iron? A) By soaking in water for extended periods. B) By using a hammer to break the iron. C) By applying a protective coating, using sacrificial anodes, or galvanizing the iron. D) By exposing to extreme heat. Show Answer Correct Answer: C) By applying a protective coating, using sacrificial anodes, or galvanizing the iron. 27. Select the one that you will prefer to make an electromagnet. A) Stainless steel. B) Soft iron. C) Steel. D) Plastic. Show Answer Correct Answer: B) Soft iron. 28. A 10 cm long wire with a cross-sectional area of 5 mm$^{3}$ has a resistance of 40 $\Omega$. It is then replaced with a wire of the same material, 20 cm long and with a cross-sectional area of 20 mm$^{3}$. What is the new resistance? A) 20 oh. B) 40 oh. C) 10 $^{} $ Oh. D) 80 oh. Show Answer Correct Answer: A) 20 oh. 29. The process of electromagnetic Induction was first discovered by: A) Oersted. B) Michael Faraday. C) Maxwell. D) Ampere. Show Answer Correct Answer: B) Michael Faraday. 30. When an electric current pass through by the conductors, the conductor ..... A) Heats up. B) Going to freeze. C) To begin crash. D) Going to melt. Show Answer Correct Answer: A) Heats up. ← PreviousRelated QuizzesScience QuizzesClass 7 QuizzesClass 7 Science Chapter 10 Electric Current And Its Effects Quiz 1Class 7 Science Chapter 10 Electric Current And Its Effects Quiz 2Class 7 Science Chapter 10 Electric Current And Its Effects Quiz 3Class 7 Science Chapter 10 Electric Current And Its Effects Quiz 4Class 7 Science Chapter 10 Electric Current And Its Effects Quiz 5Class 7 Science Chapter 10 Electric Current And Its Effects Quiz 6Class 7 Science Chapter 10 Electric Current And Its Effects Quiz 7Class 7 Science Chapter 10 Electric Current And Its Effects Quiz 8 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books