This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Physics (Part I) Chapter 7 Alternating Current – Quiz 34 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 34 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What is the condition for resonance in an L-C circuit? A) V = 0. B) Im = 0. C) R = 0. D) XL = XC. Show Answer Correct Answer: D) XL = XC. 2. What is the other name for direct current? A) AC. B) DC. C) Hertz. D) Oscilloscope. Show Answer Correct Answer: B) DC. 3. The distance from the center line to the top of a crest or to the bottom of a trough is ..... A) Amplitude. B) Cycle. C) Frequency. D) None of the above. Show Answer Correct Answer: A) Amplitude. 4. Fill in the blank:Hair growth will be ..... A) Weaker. B) Stronger. C) Faster. D) Thicker. Show Answer Correct Answer: A) Weaker. 5. What does an oscilloscope trace show for an alternating current? A) The maximum potential difference. B) The frequency. C) The resistance. D) The current direction. Show Answer Correct Answer: B) The frequency. 6. How is the frequency of an alternating current measured? A) Volts. B) Amperes. C) Hertz (Hz). D) Ohms. Show Answer Correct Answer: C) Hertz (Hz). 7. The time constant of an R-L circuit is found using what formula? A) TC=L/R. B) ABC=123. C) TC=R/L. D) None of the above. Show Answer Correct Answer: A) TC=L/R. 8. What is the voltage level after the final step-down transformer before reaching residential areas? A) 11kV. B) 33kV. C) 230V. D) 400V. Show Answer Correct Answer: C) 230V. 9. What is HZ when relating to frequency? A) Hz is cycles per second. B) Hz is cycles per minute. C) Hz is height gained per second. D) Hz is height gained per minute. Show Answer Correct Answer: A) Hz is cycles per second. 10. What does the period of a wave represent? A) The number of cycles per second. B) The amount of time for one wavelength to complete. C) The maximum amplitude of the wave. D) The distance between two peaks of the wave. Show Answer Correct Answer: B) The amount of time for one wavelength to complete. 11. The frequency of AC mains in our country is A) 30 cycles/s. B) 50 cycles/s. C) 60 cycles/s. D) 0 cycles/s. Show Answer Correct Answer: B) 50 cycles/s. 12. What is the significance of the power factor in AC circuits? A) The power factor measures the voltage in AC circuits. B) The power factor signifies the efficiency of power usage in AC circuits. C) The power factor indicates the frequency of the AC supply. D) The power factor is irrelevant in resistive circuits. Show Answer Correct Answer: B) The power factor signifies the efficiency of power usage in AC circuits. 13. In an oscillating LC circuit the maximum charge on the capacitor is Q. The charge on the capacitor when the energy is stored equally between the electric and magnetic field is A) Q/2. B) $\frac{Q}{\sqrt{3}}$. C) $\frac{Q}{\sqrt{2}}$. D) Q. Show Answer Correct Answer: C) $\frac{Q}{\sqrt{2}}$. 14. In a series LCR circuit which of the following statements is/are true/ false?1. At resonance impedance becomes minimum and current becomes maximum2. At resonance current is in phase with applied voltage3. Resonant frequency depends upon the resistance of the circuit A) T, F, F. B) F, T, F. C) T, F, T. D) T, T, F. Show Answer Correct Answer: D) T, T, F. 15. The unit of inductive reactance is: A) Ohm. B) Ampere. C) Farad. D) Henry. Show Answer Correct Answer: D) Henry. 16. Define resonance in the context of AC circuits. A) Resonance happens when the circuit is short-circuited. B) Resonance is the process of converting AC to DC. C) Resonance in AC circuits is the condition where the circuit's natural frequency matches the frequency of the applied AC signal, resulting in increased amplitude. D) Resonance occurs only in DC circuits. Show Answer Correct Answer: C) Resonance in AC circuits is the condition where the circuit's natural frequency matches the frequency of the applied AC signal, resulting in increased amplitude. 17. The unit of impedance is same as that of: A) Current. B) Voltage. C) Resistance. D) Power. Show Answer Correct Answer: C) Resistance. 18. The time constant of RC circuit is A) 1/CR. B) C/R. C) CR. D) R/C. Show Answer Correct Answer: C) CR. 19. An inductive circuit contains a resistance of 10 ohm and an inductance of 2.0 henry. If an ac voltage of 120 volt and frequency of 60 Hz is applied to this circuit, the current in the circuit would be nearly A) 0.32 amp. B) 0.16 amp. C) 0.48 amp. D) 0.80 amp. Show Answer Correct Answer: B) 0.16 amp. 20. The current that flows steadily in one direction. A) AC. B) DC. C) Induced current. D) None of these. Show Answer Correct Answer: B) DC. 21. What is different about the speed of sound waves vs. the speed of light? A) Sound waves are the FASTEST in solids (high density), while light waves are the FASTEST in gas (or no molecules). B) Sound waves are the FASTEST in gas (low density), while light waves are the FASTEST in solids. C) Both have the same speed all the time. D) Both are the FASTEST in the air or gas (low density). Show Answer Correct Answer: A) Sound waves are the FASTEST in solids (high density), while light waves are the FASTEST in gas (or no molecules). 22. Rotating Vectors are called as A) Rotating Vectors. B) Phasors. C) Tensors. D) There is no such Vector. Show Answer Correct Answer: B) Phasors. 23. If impedance of an AC circuit increases, current will: A) Increase. B) Decrease. C) Become zero. D) Remain same. Show Answer Correct Answer: B) Decrease. 24. Which of the following is a good electrical insulator? A) Copper. B) Plastic. C) Iron. D) Aluminum. Show Answer Correct Answer: B) Plastic. 25. The power is transmitted from a power house on high voltage ac because ..... A) Electric current travels faster at higher volts. B) It is more economical due to less power wastage. C) It is difficult to generate power at low voltage. D) Chances of stealing transmission lines are minimized. Show Answer Correct Answer: B) It is more economical due to less power wastage. ← 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