This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Physics (Part I) Chapter 7 Alternating Current – Quiz 10 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 10 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Which circuit can act as a radio tuner? A) R and L. B) R and C. C) L and C. D) R and diode. Show Answer Correct Answer: C) L and C. 2. A sine wave has a peak value of 354 V, What is the RMS value? A) 250 V. B) 500 V. C) 354 V. D) 200V. Show Answer Correct Answer: A) 250 V. 3. The root mean square value of AC depends upon A) Only on peak value. B) Only on the frequency of the wave. C) Only on instantaneous value of the wave. D) All of the above. Show Answer Correct Answer: A) Only on peak value. 4. A circuit has a peak voltage of 275V. What is the average voltage value? A) 120V. B) 175V. C) 190V. D) 277V. Show Answer Correct Answer: B) 175V. 5. Which of the following in the carrier wave remains constant in frequency modulation (FM)? A) Speed. B) Amplitude. C) Wavelength. D) Displacement. Show Answer Correct Answer: A) Speed. 6. All of the following have the same units except: A) Inductance. B) Capacitive reactance. C) Impedance. D) Resistance. Show Answer Correct Answer: A) Inductance. 7. In which case average power is zero? A) Pure resistor. B) Pure inductor. C) Resonant circuit. D) RL circuit. Show Answer Correct Answer: B) Pure inductor. 8. Which wire is connected to the earth pin in a plug? A) Live wire. B) Neutral wire. C) Earth wire. D) None. Show Answer Correct Answer: C) Earth wire. 9. Which device is used to generate AC power in a power station? A) Transformer. B) Generator. C) Battery. D) Rectifier. Show Answer Correct Answer: B) Generator. 10. The potential difference V and the current i flowing through an instrument in an ac circuit of frequency f are given by V=5 cos wt volts and I = 2 sin wt amperes (where w = 2pf). The power dissipated in the instrument is A) Zero. B) 10W. C) 5W. D) 2.5W. Show Answer Correct Answer: A) Zero. 11. What is the relationship between phase difference and impedance? A) Phase difference has no effect on impedance. B) Higher impedance always results in lower phase differences. C) The phase difference is directly related to the impedance, with higher reactance causing greater phase differences. D) Impedance is solely determined by resistance, not phase difference. Show Answer Correct Answer: C) The phase difference is directly related to the impedance, with higher reactance causing greater phase differences. 12. The symbol for impedance is A) L. B) X. C) Z. D) None of the above. Show Answer Correct Answer: C) Z. 13. What is the main advantage of using the National Grid? A) It generates electricity. B) It reduces electricity costs. C) It allows efficient transfer of electricity. D) It stores electricity for later use. Show Answer Correct Answer: C) It allows efficient transfer of electricity. 14. The following statement describe about an inductance except ..... A) It is the opposition that a substance offer to the current flow. B) Represented by L. C) Standard unit is Henry. D) Current always lagging voltage. Show Answer Correct Answer: A) It is the opposition that a substance offer to the current flow. 15. Measuring AC voltage by multimeter should A) Need to consider the polarity. B) No need to consider the polarity. C) Need to install in series. D) None of the above. Show Answer Correct Answer: B) No need to consider the polarity. 16. Sources of direct Current are A) DC generators and Batteries. B) DC power converters that rectify the AC. C) Solar panels. D) All the above. Show Answer Correct Answer: D) All the above. 17. Phase difference between voltage and current in pure resistor is: A) 0$^\circ$. B) 45$^\circ$. C) 90$^\circ$. D) 180$^\circ$. Show Answer Correct Answer: A) 0$^\circ$. 18. Which one below is the definition of frequency? A) One complete positive and one complete negative part of the wave. B) Time taken to complete one cycle. C) Number of cycles in one second. D) Maximum value of the AC wave. Show Answer Correct Answer: C) Number of cycles in one second. 19. How does the ability to use high voltages in AC transmission affect energy efficiency? A) It increases energy losses. B) It decreases energy losses by reducing current. C) It has no effect on energy efficiency. D) It makes the system more complex. Show Answer Correct Answer: B) It decreases energy losses by reducing current. 20. What is a key benefit of using transformers with AC? A) They can convert AC to DC. B) They can adjust voltage levels efficiently. C) They can store electrical energy. D) They can increase the frequency of AC. Show Answer Correct Answer: B) They can adjust voltage levels efficiently. 21. Current whose magnitude changes with time and direction reverses periodically A) AC. B) DC. C) Induced current. D) All of the above. Show Answer Correct Answer: A) AC. 22. What is the formula for impedance (Z) in an LCR circuit? A) Z = R + (XL-Xc). B) Z = $\sqrt{R^2 + (X_L-X_c)^2}$. C) $Z = R^2 + (XL + Xc)^2$. D) Z = R-(XL + Xc). Show Answer Correct Answer: B) Z = $\sqrt{R^2 + (X_L-X_c)^2}$. 23. What happens to the inductance when the magnetic field strength decreases? A) Increases. B) Decreases. C) Remains the same. D) Becomes zero. Show Answer Correct Answer: B) Decreases. 24. Impedance of RLC circuit at resonance is A) Maximum. B) Minimum. C) Equal to R. D) None of these. Show Answer Correct Answer: B) Minimum. 25. Which component is essential in a simple single-phase AC generator? A) Battery. B) Commutator. C) Rotor. D) Diode. Show Answer Correct Answer: C) Rotor. ← 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 11 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books