This quiz works best with JavaScript enabled. Home > Class 7 > Class 7 Science Chapter 10 Electric Current And Its Effects – Quiz 15 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 7 Science Chapter 10 Electric Current And Its Effects Quiz 15 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What is the formula for current? A) I = t/Q. B) I = W/Q. C) I = Q/t. D) I = W/t. Show Answer Correct Answer: C) I = Q/t. 2. When the bulb gets fused, its filament is broken. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 3. The frequency of D.C. is: A) 0 Hz. B) 100 Hz. C) 50 Hz. D) 60 Hz. Show Answer Correct Answer: A) 0 Hz. 4. Which of the following types of water would SINK the fastest? A) Warm and salty. B) Cold and salty. C) Warm and fresh. D) Cold and fresh. Show Answer Correct Answer: B) Cold and salty. 5. During electrolysis of water, hydrogen gas is deposited at which electrode? A) Positive electrode. B) Negative electrode. C) All the above. D) None of the above. Show Answer Correct Answer: B) Negative electrode. 6. Tick the electric apps working with mechanical effect of electric current A) Juice squeezer. B) Electric oven. C) Compass. D) Electric kettle. Show Answer Correct Answer: A) Juice squeezer. 7. Which of the following is used as a safety device? A) Resistor. B) Bulb. C) Fuse. D) Switch. Show Answer Correct Answer: C) Fuse. 8. Mary-Alice likes to bring her coffee to work each morning. However, she wonders what the best cup to bring would be if she wants her coffee to stay warm. Which of the following materials would keep Mary-Alice's coffee warm the longest? A) Paper. B) Styrofoam. C) Plastic. D) Glass. Show Answer Correct Answer: B) Styrofoam. 9. What would happen to the coiled wire in an electric motor model if there are repulsion and attraction of the magnetic poles? A) The coil fluctuates and converts electrical energy into chemical energy. B) The coil stops and changes mechanical energy into electrical energy. C) The coil rotates and changes electrical energy into mechanical energy. D) The coil remains unstable. Show Answer Correct Answer: C) The coil rotates and changes electrical energy into mechanical energy. 10. If the current at a given point in a circuit is 2.5 Amp, then how many electrons pass that point on the circuit in a time period of 1 minute.Answer: A) 9.375 x 10$^{20 }$ electrons. B) 9.375 x 10$^{21 }$ electrons. C) 9.375 x 10$^{19 }$ electrons. D) 9.375 x 10$^{18}$ electrons. Show Answer Correct Answer: A) 9.375 x 10$^{20 }$ electrons. 11. Which of the following is inflammable Substances? A) Petrol. B) Wood. C) Paper. D) Straw. Show Answer Correct Answer: A) Petrol. 12. A student wants to increase the strength of an electromagnet. Which of these is a way to make the electromagnet stronger? A) Replacing the iron core with a copper core. B) Replacing the copper wire with plastic wire. C) Wrapping the wire around the iron core fewer times. D) Increasing the electric current flowing through the wire. Show Answer Correct Answer: D) Increasing the electric current flowing through the wire. 13. What is electromagnet A) Current carrying coil of insulated wire wrapped around a piece of iron. B) Bar magnet. C) Horseshoe magnet. D) None of the above. Show Answer Correct Answer: A) Current carrying coil of insulated wire wrapped around a piece of iron. 14. What current must flow in an infinitely long straight wire to produce a magnetic field of $4\\times10^5$ A) 1.6 A. B) 16 A. C) .16 A. D) 160 A. Show Answer Correct Answer: B) 16 A. 15. What unit is used to measure voltage? A) Ohms. B) Omega. C) Volts. D) Amps. Show Answer Correct Answer: C) Volts. 16. If a material is less dense then water, it will A) Sink. B) Float. C) Be neutrally buoyant. D) Freeze. Show Answer Correct Answer: B) Float. 17. The substance used to make permanent magnet is: A) Copper. B) Aluminium. C) Alno. D) None of these. Show Answer Correct Answer: C) Alno. 18. During electroplating, the metal to be plated is at the- A) Anode. B) Cathode. C) Any would do. D) Both of them. Show Answer Correct Answer: A) Anode. 19. Th ree wires of equal lengths are bent in the form of loops. One of the loops is circle, another is a semi-circle and the third one is a square. They are placed in a uniform magnetic field and same electric current is passed through them. Which of the following loop configuration will experience greater torque? A) Circle. B) Semi-circle. C) Square. D) All of them. Show Answer Correct Answer: A) Circle. 20. Which mark is necessary on electrical appliances? A) ISI. B) Ficc. C) AGMARK. D) KSK. Show Answer Correct Answer: A) ISI. 21. A glowing filament will be? A) At a low temperature. B) At a high temperature. C) At atmospheric temperature. D) At the temperature of the ice. Show Answer Correct Answer: B) At a high temperature. 22. What kind of products contain ISI mark? A) Electrical appliances. B) Switches, Motors, Wiring Cables. C) Computers, Mobiles. D) None of the above. Show Answer Correct Answer: B) Switches, Motors, Wiring Cables. 23. ..... is an example for temporary magnet A) Electricity. B) Iron nails. C) All the above. D) None of the above. Show Answer Correct Answer: B) Iron nails. 24. A ..... is a safety device which prevents damages to electrical circuits and possible fires. A) Battery. B) Fuse. C) Wire. D) None of the above. Show Answer Correct Answer: B) Fuse. 25. What device makes a fan plugged into the wall spin? A) Generator. B) Battery. C) Electromagnet. D) Electric motor. Show Answer Correct Answer: D) Electric motor. ← 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