This quiz works best with JavaScript enabled. Home > Class 7 > Class 7 Science Chapter 10 Electric Current And Its Effects – Quiz 30 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 7 Science Chapter 10 Electric Current And Its Effects Quiz 30 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What is the power of a 20V bulb with 5A through it? A) 100W. B) 100V. C) I a. D) Sh. Show Answer Correct Answer: A) 100W. 2. What is the Coriolis effect? A) Heat transfer caused by the rising of hotter, less dense fluids and the falling of cooler, more dense fluids. B) A punk rock band. C) The apparent deflection of moving air as a result of Earth's rotation. D) The amount of matter in a given volume. Show Answer Correct Answer: C) The apparent deflection of moving air as a result of Earth's rotation. 3. If you bring a charged object near an electrically neutral surface without allowing the object to touch the surface, the charges in the surface are rearranged by A) Friction. B) Convection. C) Induction. D) Conduction. Show Answer Correct Answer: C) Induction. 4. The amount of heat present in a wire depends on A) Material. B) Length. C) Thickness. D) All of these. Show Answer Correct Answer: D) All of these. 5. If you rub a glass rod with a piece of silk, the rod becomes positively charged. This means that A) Friction destroyed electrons in the rod. B) The silk has become negatively charged. C) Protons have moved to the rod. D) Glass attracts more protons. Show Answer Correct Answer: B) The silk has become negatively charged. 6. Discuss the impact of electric current on the substances in terms of their chemical changes. A) Electric current can only cause substances to evaporate. B) Electric current can cause chemical changes in substances by breaking down molecules or causing them to react with other substances. C) Electric current has no impact on substances. D) Electric current only causes physical changes in substances. Show Answer Correct Answer: B) Electric current can cause chemical changes in substances by breaking down molecules or causing them to react with other substances. 7. Most liquids that conducts electricity are solutions of acids, bases and salts. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 8. What symbol do we use for current? A) C. B) A. C) O. D) I. Show Answer Correct Answer: D) I. 9. Why does the bulb glow when the electric current passes through it A) Due to the heating effect of the current. B) Due to the magnetic effect of the current. C) Both A and B. D) None of the above. Show Answer Correct Answer: A) Due to the heating effect of the current. 10. Students in a science class make models of deposition. What do their models show? A) How lava flows from volcanoes. B) How rocks are broken into particles. C) How rock particles build up new landforms. D) How water, ice, and wind move rock particles. Show Answer Correct Answer: C) How rock particles build up new landforms. 11. It is work done to move a unit of electrical charge from one point to another point in electric field. This refer to A) Current. B) Potential difference. C) Resistance. D) Power. Show Answer Correct Answer: B) Potential difference. 12. Copper is A) A good conductor. B) An insulator. C) A semi conductor. D) None of these. Show Answer Correct Answer: A) A good conductor. 13. The colour of insulation of neutral wire is: A) Red. B) Black. C) Green. D) Yellow. Show Answer Correct Answer: B) Black. 14. An electrolyte is a ..... A) Solid that conducts electricity. B) Liquid that conducts Electricity. C) Liquid that does not conduct electricity. D) Solid that does not conduct electricity. Show Answer Correct Answer: B) Liquid that conducts Electricity. 15. When an electric current pass through a solenoid, acts as a/an? A) Insulater. B) Electric bell. C) Resistor. D) Bar magnet. Show Answer Correct Answer: D) Bar magnet. 16. ..... instrument is used to measure the voltage. A) Ammeter. B) Ohmmeter. C) Voltmeter. D) Galvanometer. Show Answer Correct Answer: C) Voltmeter. 17. Electonic current flows from positive to negative? A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 18. When the strength of the current flowing through a coil is increased, then which of the following statements is true? A) Strength of the magnetic field decreases. B) Strength of the magnetic field increases. C) Amount of heat generated due to resistance decreases. D) Strength of the magnetic field remains constant. Show Answer Correct Answer: B) Strength of the magnetic field increases. 19. Salinity is A) The salt content of a substance. B) The Pepper content of a substance. C) The circulation of hot and cold matter. D) The weather pattern of a region. Show Answer Correct Answer: A) The salt content of a substance. 20. Like poles of a magnet will A) Repel. B) Attract. C) All the above. D) None of the above. Show Answer Correct Answer: A) Repel. 21. The distance between a positively charged object and a negatively charged object increases. If everything else remains constant, what happens to the electric force between the objects? A) The electric force decreases. B) The electric force increases. C) The electric force remains constant. D) There is not enough information to answer this question. Show Answer Correct Answer: A) The electric force decreases. 22. The magnetic field lines inside a current carrying solenoid, are: A) Along the axis and parallel to each other. B) Circular, but they do not intersect each other. C) Circular at the ends inside the solenoid. D) All of these. Show Answer Correct Answer: A) Along the axis and parallel to each other. 23. Position of a key or a switch in a circuit is A) Left to the battery. B) Right to the battery. C) Can be place anywhere in the circuit. D) Near the positive terminal of the bulb. Show Answer Correct Answer: C) Can be place anywhere in the circuit. 24. The direction of magnetic field lines due to a straight current carrying conductor B is given by: A) Maxwell's right-handed screw rule. B) Ohm's law. C) Coulomb's law. D) None of these. Show Answer Correct Answer: A) Maxwell's right-handed screw rule. 25. The acting contacts for circuit breakers are made of A) Stainless steel. B) Hard pressed carbon. C) Porcelain. D) Copper tungsten alloy. Show Answer Correct Answer: D) Copper tungsten alloy. ← PreviousNext →Related 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 8Class 7 Science Chapter 10 Electric Current And Its Effects Quiz 9Class 7 Science Chapter 10 Electric Current And Its Effects Quiz 10 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books