This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Physics (Part I) Chapter 7 Alternating Current – Quiz 36 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 36 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. A Capacitor blocks A) Only a.c. B) Only d.c. C) Both ac and dc. D) None of these. Show Answer Correct Answer: B) Only d.c. 2. Many household appliances are connected to a 230 V rms mains supply. What is the peak voltage of a household's mains supply? A) 0 V. B) 115 V. C) 230 V. D) 325 V. Show Answer Correct Answer: D) 325 V. 3. Which of the following are uses of short wave diathermy? A) Suitable for fine and coarse hair growth. B) Suitable for use with flash technique. C) Both A and B. D) None of the above. Show Answer Correct Answer: C) Both A and B. 4. What is the other name for alternating current? A) AC. B) DC. C) Hertz. D) Oscilloscope. Show Answer Correct Answer: A) AC. 5. Which of the following is a safety precaution when working with AC electricity? A) Use wet hands. B) Wear rubber gloves. C) Stand on metal surface. D) Ignore warning signs. Show Answer Correct Answer: B) Wear rubber gloves. 6. At the resonant frequency, impedance(Z) equals what? A) $R^2+\left(X_L-X_C\right)^2$. B) $R$. C) $X_C$. D) $X_L$. Show Answer Correct Answer: B) $R$. 7. Which of the following equations represent ac current A) $I=I_o\sin\left(2\pi ft\right)$. B) $I=I_o\sin\left(\frac{2\pi}{f}t\right)$. C) $I=I_o\cos\left(\omega t\right)$. D) $I=I_o\cos\left(t\right)$. Show Answer Correct Answer: A) $I=I_o\sin\left(2\pi ft\right)$. 8. Which of the following waves are produced by moving electric and magnetic fields? A) Ultra magnetic. B) Magnetic. C) Electromagnetic. D) Electronic. Show Answer Correct Answer: C) Electromagnetic. 9. The cause of induced e.m.f. in a closed coil is A) Magnetic field. B) Magnetic flux. C) Change in magnetic flux. D) None of these. Show Answer Correct Answer: C) Change in magnetic flux. 10. Satuan dari Impedansi (Z) adalah Ohm A) BENAR. B) SALAH. C) All the above. D) None of the above. Show Answer Correct Answer: A) BENAR. 11. The impedance of a circuit consists of 3 ohm resistance and 4 ohm reactance. The power factor of the circuit is ..... A) 0.4. B) 0.6. C) 0.8. D) 1.0. Show Answer Correct Answer: B) 0.6. 12. What is the opposition to AC by an inductor called? A) Inductive Reactance. B) Capacitive Reactance. C) Impedance. D) Resistance. Show Answer Correct Answer: A) Inductive Reactance. 13. A pure capacitor is connected to an AC power supply. In this circuit, the current A) Leads the voltage by 90$^\circ$. B) Lags the voltage by 90$^\circ$. C) Is in phase with the voltage. D) None of the given answers. Show Answer Correct Answer: A) Leads the voltage by 90$^\circ$. 14. In an inductive AC circuit, when the applied voltage is at its maximum negative value, the current is ..... A) Zero. B) Increasing toward maximum positive. C) At the maximum negative value. D) At the maximum positive value. Show Answer Correct Answer: A) Zero. 15. What is the term for the overall resistance in an RLC circuit? A) Impedance. B) Voltage. C) Current. D) Reactance. Show Answer Correct Answer: A) Impedance. 16. What is produced when the conductor crosses the lines of force at 90$^\circ$? A) No emf. B) Maximum negative emf. C) Maximum positive emf. D) Constant voltage. Show Answer Correct Answer: C) Maximum positive emf. 17. For a given AC source, maximum average power is dissipated when circuit is: A) Purely inductive. B) Purely capacitive. C) Resonant. D) Open. Show Answer Correct Answer: C) Resonant. 18. The frequency of DC in our country is A) 30 cycles/s. B) 50 cycles/s. C) 60 cycles/s. D) 0 cycles/s. Show Answer Correct Answer: D) 0 cycles/s. 19. What is the effect of the speed of the conductor on the generation of emf? A) It increases the emf. B) It only affects the frequency. C) It decreases the emf. D) It has no effect. Show Answer Correct Answer: A) It increases the emf. 20. A bulb is connected with an AC source through an inductor.How the glow of the bulb will be affected if an iron rod is inserted in the core of the inductor A) It will increase. B) It will decrease. C) Remain same. D) The bulb will stop glowing. Show Answer Correct Answer: B) It will decrease. 21. A bike-dynamo is rotated by hand, with its terminals attached to the inputs of a CRO. If it is rotated twice as fast, A) The amplitude and frequency of the voltage will both double. B) The amplitude will double and the frequency will be unchanged. C) The amplitude will be unchanged and the frequency will double. D) The amplitude will increase by four times and the frequency will double. Show Answer Correct Answer: A) The amplitude and frequency of the voltage will both double. 22. Peak to Peak voltage is A) Tmax-tmin. B) Tmax-Tmin. C) Vmax-0. D) Vmax-Vmin. Show Answer Correct Answer: D) Vmax-Vmin. 23. A series RLC circuit has a resistance of 10.0 $\Omega$ and a impedance of 50.0 $\Omega$. If the rms voltage applied to the circuit is 10 V, what average power? A) 0.4W. B) 4W. C) 5W. D) 50W. Show Answer Correct Answer: A) 0.4W. 24. A series RLC circuit is connected across a 240V, 50 Hz supply. When the voltage across capacitor is 250V, a maximum current of 0.5A flows in the circuit. Find the resistance. A) 480 Ohms. B) 500 Ohms. C) 100 Ohms. D) 1000 Ohms. Show Answer Correct Answer: A) 480 Ohms. 25. What is a primary advantage of AC over DC in terms of infrastructure? A) AC requires less complex infrastructure for voltage transformation. B) AC infrastructure is more expensive to build. C) AC infrastructure is more prone to weather damage. D) AC infrastructure requires more frequent maintenance. Show Answer Correct Answer: A) AC requires less complex infrastructure for voltage transformation. ← 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