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 ⇒ B |
2. The dimensional formula of L/R is similar to that of:
(A) frequency
(B) time
(C) length
(D) none of these
| Answer ⇒ B |
3. Which of the following has dimensions different from the rest ?
(A) L/R
(B) 1/RC
(C) √LC
(D) RC
| Answer ⇒ 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 ⇒ B |
5. Energy dissipates in LCR circuit in:
(A) L only
(B) C only
(C) R only
(D) All of the above
| Answer ⇒ 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 ⇒ B |
7. The SI unit of magnetic flux is :
(A) T
(B) Tn-2
(C) Wb
(D) Wb m-2
| Answer ⇒ C |
8. For purely capacitive circuits, power factor is :
(A) O
(B) -1
(C) 1
(D) infinity
| Answer ⇒ 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 ⇒ 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 ⇒ 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 ⇒ 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 ⇒ 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 ⇒ D |
14. What is the ratio of inductive and capacitance reactances in an ac circuit ?
(A) 1
(B) ω2L
(C) ω2LC
(D) 1
| Answer ⇒ C |
15. An acceptor circuit is :
(A) series resonant circuit
(B) parallel resonant circuit
(C) LCR circuit
(D) None of these
| Answer ⇒ A |
16. In series resonant circuit :
(A) reactance is zero
(B) current is zero
(C) voltage is zero
(D) None of these
| Answer ⇒ 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 ⇒ A |
Class 12th physics objective question in English
