This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Physics (Part I) Chapter 7 Alternating Current – Quiz 30 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 30 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. The distance of the waveform travel in one cycle is referred to A) Amplitude. B) Wavelength. C) Time. D) Frequency. Show Answer Correct Answer: B) Wavelength. 2. The Analog of resistance in a purely inductive circuit is called A) Inductive Resistance. B) Inductive Reactance. C) Impedance. D) Admittance. Show Answer Correct Answer: B) Inductive Reactance. 3. The time required for one cycle of events to occur is known as A) Period. B) Headache. C) Mind-numbing. D) None of the above. Show Answer Correct Answer: A) Period. 4. The phase difference between voltage and current in a purely inductive circuit A) 0. B) 90. C) -90. D) 180. Show Answer Correct Answer: C) -90. 5. If the current in an inductor is tripled, by what factor does the stored energy change? A) 4.5. B) 2. C) 1/9. D) 9. Show Answer Correct Answer: D) 9. 6. A dry-cell battery produces ..... A) An alternating current. B) A direct current. C) Both direct and alternating current. D) The same current that a generator produces. Show Answer Correct Answer: B) A direct current. 7. In a pure capacitor ac circuit A) Current lead voltage by 90'. B) Voltage lead current by 90'. C) Both current and voltage are in phase. D) Current and voltage are out of phase. Show Answer Correct Answer: A) Current lead voltage by 90'. 8. What is a common method used to reduce energy losses in AC power lines? A) Increasing the frequency of the AC. B) Using superconducting materials. C) Transmitting at high voltages. D) Converting AC to DC. Show Answer Correct Answer: C) Transmitting at high voltages. 9. The RMS value of an AC Wave is the A) Effective DC Value. B) Average value. C) Some made up value. D) None of the above. Show Answer Correct Answer: A) Effective DC Value. 10. What is an Alternating Current? A) An electric current that never changes direction. B) An electric current that changes direction many times. C) An electric current that has no frequency. D) A current that has no electrical properties. Show Answer Correct Answer: B) An electric current that changes direction many times. 11. How does voltage affect electrical currents? A) The voltage of an object has no effect on the current. B) If the voltage in the object increases the current will decrease. C) If the voltage in the object decreases the current will increase. D) If the voltage in the object increases the current will increase. Show Answer Correct Answer: D) If the voltage in the object increases the current will increase. 12. Find the maximum power dissipated in the circuit A) 2299.3 W. B) 5500 W. C) 2200 W. D) 4700 W. Show Answer Correct Answer: A) 2299.3 W. 13. Explain the concept of frequency in AC circuits. A) Frequency is the resistance in an AC circuit. B) Frequency is the voltage level in an AC circuit. C) Frequency is the number of cycles per second in an AC circuit, measured in hertz (Hz). D) Frequency is the amount of current flowing in an AC circuit. Show Answer Correct Answer: C) Frequency is the number of cycles per second in an AC circuit, measured in hertz (Hz). 14. What type of current is typically used in electronic devices? A) Direct current B) Alternating current C) Both A and B D) None of the above A) High frequency current. B) Pulsating current. C) Static current. D) A) Direct current. Show Answer Correct Answer: D) A) Direct current. 15. A coil intercepts a magnetic flux of 0.2 x 10$^{-2}$ Wb in 0.1s. What is the emf induced in the coil? A) 0.2V. B) 0.002V. C) 2V. D) 0.02V. Show Answer Correct Answer: D) 0.02V. 16. The combine opposition of resistor, capacitor and inductor is called A) Reactance. B) Resistor. C) Impedance. D) None. Show Answer Correct Answer: C) Impedance. 17. How does RMS voltage differ from average voltage? A) RMS voltage is higher than average voltage for AC signals, as it represents the effective value. B) RMS voltage and average voltage are identical for all waveforms. C) RMS voltage is always lower than average voltage. D) Average voltage is used exclusively for DC signals. Show Answer Correct Answer: A) RMS voltage is higher than average voltage for AC signals, as it represents the effective value. 18. In a pure inductor circuit, ..... A) The current and voltage are in antiphase. B) The voltage leads current by $\frac{\pi}{2}$. C) The current leads voltage by $\frac{\pi}{2}$. D) The current and voltage are in phase. Show Answer Correct Answer: B) The voltage leads current by $\frac{\pi}{2}$. 19. What is the term for the difference between half power points in a resonance curve? A) Impedance. B) Bandwidth. C) Reactance. D) Q-factor. Show Answer Correct Answer: B) Bandwidth. 20. What will happen, if we connect capacitor to DC Supply. A) It allows DC. B) It blocks DC. C) T rectifies. D) None of these. E) Hint:Diode is unidirectional and uncontrolled device. In rectifier circuit, diode use as a switch to convert ac to dc for rectification purpose. Show Answer Correct Answer: B) It blocks DC. 21. Cauterisation uses a high intensity, high frequency current which is absorbed by the skin tissues and leads to the water molecules within the tissues being vapourised, drying out the tissues by ..... ? A) Electro-desiccation. B) Electro-coagulation. C) Electrolysis. D) Electro-fulguration. Show Answer Correct Answer: A) Electro-desiccation. 22. Power equals A) Voltage divided by current. B) Voltage multiplied by resistance. C) Voltage. D) Voltage multiplied by current. Show Answer Correct Answer: D) Voltage multiplied by current. 23. Alternating current differs from direct current because ..... A) It alternates from AC to DC. B) The current alternates between 2 A and 5 A. C) It changes direction. D) The resistance fluctuates back and forth. Show Answer Correct Answer: C) It changes direction. 24. What is the principle of the transformer? A) Ampere's law. B) Mutual induction. C) Coulomb's law. D) Gauss law. Show Answer Correct Answer: B) Mutual induction. 25. A student is comparing AC and DC for use in household appliances. What evidence supports the use of AC for most appliances? A) AC is more expensive to generate. B) AC can be easily transformed to different voltages and is compatible with the power grid. C) DC is more common in homes. D) DC is safer for all appliances. Show Answer Correct Answer: B) AC can be easily transformed to different voltages and is compatible with the power grid. ← 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