A. reduce eddy current loss
B. increase heat radiation
C. make assembly cheap and easier
D. reduce circuit permeability
Related Mcqs:
- A heater is rated as 230 V, 10 kW, A.C. The value 230 V refers to__________?
A. average voltage
B. r.m.s. voltage
C. peak voltage
D. none of the above - The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of____________?
A. iron loss in core
B. skin effect
C. increase in temperature
D. capacitive effect between adjacent coil turns - All the rules and laws of D.C. circuit also apply to A.C. circuit containing_____________?
A. capacitance only
B. inductance only
C. resistance only
D. all above - Capacitive reactance is more when_______?
A. capacitance is less and frequency of supply is less
B. capacitance is less and frequency of supply is more
C. capacitance is more and frequency of supply is less
D. capacitance is more and frequency of supply is more - Inductance of a coil Varies__________?
A. directly as the cross-sectional area of magnetic core
B. directly as square of number of turns
C. directly as the permeability of the core
D. inversely as the length of the iron path
E. as A. to (d) - The power factor at resonance in R-L- C parallel circuit is________?
A. zero
B. 0.08 lagging
C. 0.8 leading
D. unity - The phosphors for which of the following pair are 180° out of phase for VL, VC and VR______?
A. Vc and VR
B. VL and VR
C. Vc and VL
D. none of the above - At very low frequencies a series R-C circuit behaves as almost purely___________?
A. resistive
B. inductive
C. capacitive
D. none of the above - Wire-wound resistors are unsuitable for use at high frequencies because they_______?
A. create more electrical noise
B. are likely to melt under excessive eddy current heat
C. consume more power
D. exhibit unwanted inductive and capacitive effects - The time constant of a series R-C circuit is given by____________?
A. R/C
B. RC2
C. RC
D. R2C
