7. ALTERNATING CURRENT( Objective Question Answer 2022 )


1. Power factor of an ac circuit is a measure of:

(A) virtual power
(B) power lost in the circuit
(C) mean power
(D) all the above

Answer тЗТ B

2. The dimensional formula of L/R is similar to that of:

(A) frequency
(B) time
(C) length
(D) none of these

Answer тЗТ B

3. Which of the following has dimensions different from the rest ?

(A) L/R
(B) 1/RC
(C) тИЪLC
(D) RC

Answer тЗТ B

4. The dimensional formula of impedance is :

(A) [ML2T-2A-2]
(B) [ML2T-3A-2]
(C) [ML2T-2A-1]
(D) [ML2T-2A-3]

Answer тЗТ B

5. Energy dissipates in LCR circuit in:

(A) L only
(B) C only
(C) R only
(D) All of the above

Answer тЗТ C

6. A choke is used as a resistance in :

(A) de circuits
(B) ac circuits
(C) both ac and dc circuits
(D) neither (A) nor (B)

Answer тЗТ B

7. The SI unit of magnetic flux is :

(A) T
(B) Tn-2
(C) Wb
(D) Wb m-2

Answer тЗТ C

8. For purely capacitive circuits, power factor is :

(A) O
(B) -1
(C) 1
(D) infinity

Answer тЗТ A

9. The magnetic flux linked with a coil is inversely proportional to the :

(A) magnetic field
(B) area of cross section
(C) number of turns
(D) none of these

Answer тЗТ A

10. When the magnetic field is parallel to a surface, then the magnetic flux through the surface is :

(A) infinite
(B) zero
(C) small but not zero
(D) large but not infinite

Answer тЗТ B

11. The dimensional formula of induced emf is :

(A) [ML2T-2A-1]
(B) [ML2T-3A-1]
(C) [ML2T-3A-2]
(D) [ML2T-2A-2]

Answer тЗТ B

12. The dimensional formula of the coefficient of self inductance is :

(A) [ML2T-2]
(B) [ML2T-3A-1]
(C) [ML2T-2A-2]
(D) [ML2T-3A-2]

Answer тЗТ C

13. The motional emf produced across moving through a magnetic field does depend on its:

(A) length
(B) velocity
(C) orientation
(D) diameter

Answer тЗТ D

14. What is the ratio of inductive and capacitance reactances in an ac circuit ?

(A) 1
(B) ╧Й2L
(C) ╧Й2LC
(D) 1

Answer тЗТ C

15. An acceptor circuit is :

(A) series resonant circuit
(B) parallel resonant circuit
(C) LCR circuit
(D) None of these

Answer тЗТ A

16. In series resonant circuit :

(A) reactance is zero
(B) current is zero
(C) voltage is zero
(D) None of these

Answer тЗТ D

17. In parallel resonant circuit ;

(A) impedance is very high
(B) current is very high
(C) voltage is very high
(D) None of these

Answer тЗТ A

Class 12th physics objective question in English

S.N Physics Objective English Medium
1. ┬аELECTRIC CHARGES AND FIELDS
2. LECTROSTATIC POTENTIAL AND CAPACITANCE
3. CURRENT ELECTRICITY
4. MOVING CHARGES AND MAGNETISM
5. MAGNETISM AND MATTER
6. ELECTROMAGNETIC INDUCTION
7. ALTERNATING CURRENT
8. ELECTROMAGNETIC WAVES
9. RAY OPTICS AND OPTICAL INSTRUMENTS
10. WAVE OPTICS
11. DUAL NATURE OF MATTER AND RADIATION
12. ATOMS
13. NUCLEI
14. SEMI CONDUCTOR ELECTRONICS┬а
15. COMMUNICATION SYSTEMS

 

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