Alternating Current - Quiz 4

ALTERNATING CURRENT QUIZ-4

Dear Readers,

JEE Advanced Physics Syllabus can be referred by the IIT aspirants to get a detailed list of all topics that are important in cracking the entrance examination. JEE Advanced syllabus for Physics has been designed in such a way that it offers very practical and application-based learning to further make it easier for students to understand every concept or topic by correlating it with day-to-day experiences. In comparison to the other two subjects, the syllabus of JEE Advanced for physics is developed in such a way so as to test the deep understanding and application of concepts.

Q1. The peak value of an alternating emf E given by E=E₀cos⁡ωt is 10 V and frequency is 50 Hz. At time t=(1/600) s, the instantaneous value of emf is

•  10 V
•  5√3 V
•  5 V
•  1 V

Solution

Q2. An inductor and a resistor are connected in series with an ac source. In this circuit

•  0.1 A
•  0.3 A
•  0.6 A
•  0.2 A

Solution

Q3. An ac voltage is represented by E=220 √2cos⁡(50 π)t. How many times will the current become zero in 1 s?

•  50 times
•  100 times
•  30 times
•  25 times

Solution

Q4. In series LCR circuit voltage drop across resistance is 8 V, across inductor is 6 V and across capacitor is 12 V. Then

•  Voltage of the source will be leading current in the circuit
•  Voltage drop across each element will be less than the applied voltage
•  Power factor of circuit will be 4/3
•  None of these

Solution

Q5. Using an ac voltmeter, the potential difference in the electrical line in a house is read to be 234 V. If the line frequency is known to be 50 cycles/second, the equation for the line voltage is

•  V=165 sin⁡(100 πt)
•  V=331 sin⁡(100 πt)
•  V=220 sin⁡(100 πt)
•  V=440 sin⁡(100 πt)

Solution

Q6. An alternating voltage E=50 √2 sin⁡(100 t) V is connected to a 1 μ F capacitor through an ac ammeter. What will be the reading of the ammeter?

•  10 mA
•  5 mA
•  5√2 mA
•  10√2 mA

Solution

Q7. In LCR circuit current resonant frequency is 600 Hz and half power points are at 650 and 550 Hz. The quality factor is

•  1/6
•  1/3
•  6
•  3

Solution

Q8. The power factor of the circuit in Fig is 1/√2. The capacitance of the circuit is equal to

•  400 μF
•  300 μF
•  500 μF
•  200 μF

Solution

Q9. In the circuit shown in Fig, X_C=100 Ω,X_L=200 Ωand R=100 Ω. The effective current through the source is

•  2 A
•  2√2 A
•  0.5 A
•  √0.4A

Solution

Q10. A 220-V, 50 Hz ac generator is connected to an inductor and a 50 Ω resistance in series. The current in the circuit is 1.0 A. What is the pd across inductor?

•  102.2 V
•  186.4 V
•  214 V
• 170 V

Solution