This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Physics (Part I) Chapter 7 Alternating Current – Quiz 11 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 11 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. The power that is distributed from a power plant to your home is: A) High voltage to high voltage. B) Low voltage to high voltage. C) High voltage to low voltage. D) Low voltage to low voltage. Show Answer Correct Answer: C) High voltage to low voltage. 2. If the phase difference is 0 degree, the circuit is purely ..... A) Capacitive. B) Resistive. C) Inductive. D) None of these. Show Answer Correct Answer: B) Resistive. 3. An electric fan is: A) Electric motor. B) Electric generator. C) An accelerator. D) Based on electromagnetic induction. Show Answer Correct Answer: A) Electric motor. 4. State whether the following statements is TRUE or FALSE;The magnitude of magnetic field of an electromagnetic wave does not depend on position (x). A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 5. (d) A 100 W lamp is designed for use with 110 V ac What is the resistance of its filament? A) 100ohms. B) 221ohms. C) 121ohms. D) 0 ohm. Show Answer Correct Answer: C) 121ohms. 6. What is required to use an electric appliance? A) Use a solar cell. B) Connect it to a power plant. C) Plug it into an outlet. D) Use a fuel cell. Show Answer Correct Answer: C) Plug it into an outlet. 7. RMS stands for ..... A) Root mean Squared value. B) Remote Monitoring System. C) All the above. D) None of the above. Show Answer Correct Answer: A) Root mean Squared value. 8. What is the potential difference of alternating current in the UK? A) 50 Hertz. B) 230 volts. C) Not mentioned. D) Cannot be determined. Show Answer Correct Answer: B) 230 volts. 9. The opposition of a resistor to the alternating current flow is known as A) Inductive reactant. B) Capacitive reactant. C) Resistance. D) None of the above. Show Answer Correct Answer: C) Resistance. 10. Direction of induced current is determined by ..... A) Right hand thumb rule. B) Fleming's left hand rule. C) Fleming's right hand rule. D) Faraday's law. Show Answer Correct Answer: C) Fleming's right hand rule. 11. What happens to the value of voltage as the conductor travels from parallel to crossing the lines of force? A) It builds from 0 to a maximum positive value. B) It decreases steadily. C) It fluctuates randomly. D) It remains at zero. Show Answer Correct Answer: A) It builds from 0 to a maximum positive value. 12. What is the significance of the density of the magnetic flux in emf generation? A) It determines the color of the conductor. B) It affects the amount of emf generated. C) It has no significance. D) It only affects the speed of the conductor. Show Answer Correct Answer: B) It affects the amount of emf generated. 13. A power transmission line feeds power at 2200 V with a current of 5 A to a step-down transformer whose primary has 4000 turns. To obtain 220 V output, how many turns should be in the secondary? A) 200 turns. B) 400 turns. C) 800 turns. D) 4000 turns. Show Answer Correct Answer: B) 400 turns. 14. A pure inductor is connected to an a.c. source of frequency 100 Hz and the r.m.s. value of the voltage is 12 V. If the peak value of the current flowing through the inductor is 14 A, what is the inductance of the inductor? A) 1.6 mH. B) 1.9 mH. C) 30 mH. D) 39 mH. Show Answer Correct Answer: B) 1.9 mH. 15. Which factor increases rms value of current? A) Increase in impedance. B) Decrease in voltage. C) Increase in peak voltage. D) Increase in phase angle. Show Answer Correct Answer: C) Increase in peak voltage. 16. What is the relationship between frequency and the output voltage in an AC generator? A) Frequency has no effect on voltage. B) Higher frequency results in higher voltage. C) Higher frequency results in lower voltage. D) Voltage is constant regardless of frequency. Show Answer Correct Answer: B) Higher frequency results in higher voltage. 17. How can the 'ripples' in a smoothed output voltage graph be reduced? A) By increasing the load resistance. B) By increasing the peak voltage. C) By using a larger capacitor. D) By decreasing the frequency. Show Answer Correct Answer: C) By using a larger capacitor. 18. What are the conditions for resonance to occur in an RLC circuit? A) Inductive reactance is always greater than capacitive reactance. B) Resonance occurs at any frequency regardless of reactance. C) Inductive reactance equals capacitive reactance (XL = XC) at the resonant frequency. D) The circuit must have a resistor value of zero. Show Answer Correct Answer: C) Inductive reactance equals capacitive reactance (XL = XC) at the resonant frequency. 19. Describe the effect of capacitance on the phase angle in AC circuits. A) Capacitance causes the voltage to lead the current, decreasing the phase angle in AC circuits. B) Capacitance has no effect on the phase angle in AC circuits. C) Capacitance causes the current and voltage to be in phase, resulting in a phase angle of zero. D) Capacitance causes the current to lead the voltage, increasing the phase angle in AC circuits. Show Answer Correct Answer: D) Capacitance causes the current to lead the voltage, increasing the phase angle in AC circuits. 20. An alternating current is set up in an LRC circuit. For which of the following circuit elements are the current and voltage in phase? A) Inductor only. B) Resistor only. C) Capacitor only. D) Resistor and capacitor only. Show Answer Correct Answer: B) Resistor only. 21. What is the role of a rectifier in converting AC to DC? A) A rectifier converts DC to AC using transformers to increase voltage. B) A rectifier is used to amplify AC signals for better transmission. C) A rectifier converts AC to DC by allowing current to flow in one direction, using diodes to block reverse flow. D) A rectifier allows current to flow in both directions, enabling bidirectional flow. Show Answer Correct Answer: C) A rectifier converts AC to DC by allowing current to flow in one direction, using diodes to block reverse flow. 22. The unit of measurement of the ability of a capacitor to store an electrical charge is the A) Farad. B) Ohm. C) Amp. D) None of the above. Show Answer Correct Answer: A) Farad. 23. Which statement is correct for AC? A) Direction is constant. B) Magnitude is constant. C) Both change with time. D) Neither changes. Show Answer Correct Answer: C) Both change with time. 24. Inductance in an AC circuit causes the current to A) Lead the voltage. B) Lag the voltage. C) Remain in phase with the voltage. D) None of the above. Show Answer Correct Answer: B) Lag the voltage. 25. In pure resistive AC circuit, instantaneous value of voltage or current: A) Current lags behind voltage. B) Current leads voltage by 90. C) Both are in-phase. D) Voltage leads current by 90. Show Answer Correct Answer: C) Both are in-phase. ← PreviousNext →Related QuizzesClass 12 Physics (Part I) Chapter 7 Alternating Current Quiz 1Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 2Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 3Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 4Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 5Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 6Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 7Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 8Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 9Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 10 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books