This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Physics (Part I) Chapter 7 Alternating Current – Quiz 33 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 7 Alternating Current Quiz 33 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Which of the following is a benefit of using AC for power distribution in cities? A) AC is less affected by electromagnetic interference. B) AC allows for easy voltage transformation to meet different needs. C) AC is more stable in extreme weather conditions. D) AC requires less infrastructure. Show Answer Correct Answer: B) AC allows for easy voltage transformation to meet different needs. 2. What is the mean power dissipated in a resistor connected to an alternating voltage? A) The product of peak voltage and peak current. B) The product of r.m.s. voltage and r.m.s. current. C) The sum of all power values over a cycle. D) The average of instantaneous power. Show Answer Correct Answer: B) The product of r.m.s. voltage and r.m.s. current. 3. What is the true power in a 2A series RL circuit with a 100$\Omega$ resistor? A) 50W. B) 200W. C) 400W. D) 600W. Show Answer Correct Answer: C) 400W. 4. A heater is rated as 230 V, 10 kW. The value 230 V refers to A) Average voltage. B) Peal voltage. C) R.m.s voltage. D) None of the above. Show Answer Correct Answer: C) R.m.s voltage. 5. An alternating current is one that ..... A) Changes direction periodically. B) Flows in a fixed direction. C) Changes only magnitude periodically. D) Has a fixed magnitude. Show Answer Correct Answer: A) Changes direction periodically. 6. A vector quantity has A) Only magnitude. B) Only direction. C) Both (a) and (b). D) None of these. Show Answer Correct Answer: C) Both (a) and (b). 7. Which graph represents current and voltage in capacitive circuit? A) In phase. B) Current ahead of voltage. C) Voltage ahead of current. D) Both zero. Show Answer Correct Answer: B) Current ahead of voltage. 8. What is the term for the opposition to current flow in an inductor? A) Resistance. B) Capacitive reactance. C) Inductive reactance. D) Impedance. Show Answer Correct Answer: C) Inductive reactance. 9. Which of the following conditions exists in a circuit of pure resistance? A) The voltage and current are 180$^\circ$ out of phase. B) The voltage and current are 270$^\circ$ out of phase. C) The voltage and current are 90$^\circ$ out of phase. D) The voltage and current are in phase. Show Answer Correct Answer: D) The voltage and current are in phase. 10. A family wants to use solar panels to power their home. What device is needed to convert the DC output of solar panels to AC for household use? A) Transformer. B) Inverter. C) Capacitor. D) Fuse. Show Answer Correct Answer: B) Inverter. 11. A transformer has an efficiency of 80%. It works at 4kW and 100V. If secondary voltage is 240V, the current in primary coil is A) 0.4A. B) 4A. C) 10A. D) 40A. Show Answer Correct Answer: D) 40A. 12. In a purely resistive AC circuit where 240V is applied across a 10$\Omega$ resistor, the amperage is ..... A) 120A. B) 10A. C) 24A. D) 60A. Show Answer Correct Answer: C) 24A. 13. The quantity that limits AC more at high frequency: A) Resistance. B) Capacitance. C) Inductance. D) Emf. Show Answer Correct Answer: C) Inductance. 14. In an RLC circuit, power loss can take place in A) R. B) L. C) C. D) L and C. Show Answer Correct Answer: A) R. 15. Induced emf in a conductor of length l moving perpendicular to uniform magnetic field B with velocity v is A) E = Blv. B) E = Bl/v. C) E = Bv/l. D) E = Bv$^{2}$l. Show Answer Correct Answer: A) E = Blv. 16. How does impedance affect the flow of current in an AC circuit? A) Higher impedance leads to an increase in current flow. B) Impedance has no effect on current flow in an AC circuit. C) Impedance in an AC circuit causes a direct current flow. D) Impedance affects the flow of current in an AC circuit by resisting it. Higher impedance leads to a decrease in current flow. Show Answer Correct Answer: D) Impedance affects the flow of current in an AC circuit by resisting it. Higher impedance leads to a decrease in current flow. 17. The opposition to the flow of alternating current offered by a capacitor is called A) Capacitance. B) Inductive Reactance. C) Capacitive Reactance. D) None of the above. Show Answer Correct Answer: C) Capacitive Reactance. 18. A lamp is connected to a sinusoidal supply. The maximum power transferred by the lamp is 50 W. What is the average power of the lamp. A) 10 W. B) 25 W. C) 50 W. D) 100 W. Show Answer Correct Answer: B) 25 W. 19. What is the frequency of ac mains in India? A) 120 Hz. B) 60 Hz. C) 50 Hz. D) 30 Hz. Show Answer Correct Answer: C) 50 Hz. 20. Which of the following consumes net power in one cycle? A) Inductor. B) Capacitor. C) Resistance. D) All Devices consume Zero Average Power. Show Answer Correct Answer: C) Resistance. 21. Which of the following is NOT a source of direct current? A) Batteries. B) Fuel cells. C) Power plants. D) Solar cells. Show Answer Correct Answer: C) Power plants. 22. What is the purpose of a commutator in an AC generator? A) To convert AC to DC. B) To reverse the direction of current. C) To maintain a constant voltage output. D) To increase the frequency of the output. Show Answer Correct Answer: A) To convert AC to DC. 23. What is the main advantage of using AC over DC for power transmission? A) AC is easier to generate. B) AC can be easily transformed to different voltages. C) AC is safer to use. D) AC requires less maintenance. Show Answer Correct Answer: B) AC can be easily transformed to different voltages. 24. Which of the following choices best gives the benefit(s) of using AC over using DC? A) The length of wires is less relevant. B) Power may be transferred over long distances using higher voltage and low current. C) The potential difference may be varied using transformers. D) All of the above answers are benefits of AC over DC. Show Answer Correct Answer: D) All of the above answers are benefits of AC over DC. 25. In an LCR circuit A) Impedance is equal to reactance. B) The ratio between effective voltage to effective current is called reactance. C) At resonance the resistance is equal to the reactance. D) At resonance the net reactance is zero. Show Answer Correct Answer: D) At resonance the net reactance is zero. ← 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