Module Exercise 3 - AC PDF

Physicsaholics Module AC (Physicsaholics) Physicsaholics.com Unacademy...

Physicsaholics Module AC (Physicsaholics) Physicsaholics.com Unacademy Exercise-3 (Miscellaneous Type) Kota Modules refined by Physicsaholics Team. Use code PHYSICSLIVE to get Maximum OFF on Unacademy PLUS / Iconic and learn from India’s Top Faculties. 1  Physicsaholics Direction for Assertion & Reason question These question consist of two statements each, printed as Assertion and Reason. While answering these Question you are required to choose any one of the following four responses (A) If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion. (B) If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion. (C) If Assertion is True but the Reason is False. (D) If both Assertion & Reason are False. Q 1. Assertion : Power loss in ideal choke coil is zero. Reason : Ideal choke coil has zero resistance. (1) A (2) B (3) C (4) D Q 2. Assertion: Average power loss in series LC circuit is always zero. Reason : Average values of voltage and current in A. C. is zero. (1) A (2) B (3) C (4) D Q 3. Assertion :Average of sinusoidal A. C. can never be zero for half cycle. Reason : Impedance given by inductance does not depends on frequency. (1) A (2) B (3) C (4) D Q 4. Assertion : The division are equally marked on the scale of A.C. ammeter. Reason : Heat produced is directly proportional to the current. (1) A (2) B (3) C (4) D Q 5. Assertion : The alternating current lags behind the e.m.f. by a phase angle of /2, when A. C. flows through an inductor. Reason : The inductive reactance increases as the frequency of A.C. source decreases. (1) A (2) B (3) C (4) D Q 6. Assertion : Capacitor serves as a block for D.C. and offers an easy path to A.C. Reason : Capacitive reactance is inversely proportional to frequency. (1) A (2) B (3) C (4) D Kota Modules refined by Physicsaholics Team. Use code PHYSICSLIVE to get Maximum OFF on Unacademy PLUS / Iconic and learn from India’s Top Faculties. 2  Physicsaholics Q 7. Assertion : Choke ·coil is preferred over a resistor to adjust current in an A.C. circuit. Reason : Power factor for inductance is zero, so power loss is also zero. (1) A (2) B (3) C (4) D Q 8. Assertion : The resistance of a coil for direct current is 5 ohm. An alternating current is sent through it. The resistance will remain same. Reason : The resistance of a coil does not depend upon nature of current. (1) A (2) B (3) C (4) D Q 9. Assertion : When capacitive reactance is smaller then the inductive reactance in series LCR circuit, voltage leads the current. Reason : In series LCR circuit inductive reactance is always greater then capacitive reactance. (1) A (2) B (3) C (4) D Q 10. Assertion : In series RL ac circuit voltage leads the current. Reason : In series RC ac circuit current leads the voltage. (1) A (2) B (3) C (4) D Q 11. Assertion : An alternating current of frequency 50 Hz becomes zero, 100 times in one second. Reason : Alternating current changes direction and becomes zero twice in a cycle. (1) A (2) B (3) C (4) D 12. Assertion : A sinusoidal alternating current does not show any average magnetic effects. Reason : The average value of an alternating current is zero. (1) A (2) B (3) C (4) D 13. Assertion : The dc and ac both can be measured by a hot wire instrument. Reason : The hot wire instrument is based on the principle of heating effect of current. (1) A (2) B (3) C (4) D Kota Modules refined by Physicsaholics Team. Use code PHYSICSLIVE to get Maximum OFF on Unacademy PLUS / Iconic and learn from India’s Top Faculties. 3 14. Physicsaholics For series RLC as circuit graph between current and frequency of voltage source is shown in figure. Assertion : Nature of circuit in. region (1) is capacitive while in region (2) is inductive. Reason : Power factor of circuit in region (1) is negative and in region (2) is positive. (1) A (2) B (3) C (4) D Answer Key Q.1) 1 Q.2) 2 Q.3) 4 Q.4) 4 Q.5) 3 Q.6) 1 Q.7) 1 Q.8) 1 Q.9) 3 Q.10) 2 Q.11) 1 Q.12) 1 Q.13) 1 Q.14) 3 Kota Modules refined by Physicsaholics Team. Use code PHYSICSLIVE to get Maximum OFF on Unacademy PLUS / Iconic and learn from India’s Top Faculties. 4