NEET Physics Alternating Current Questions Solved

BOARD

An inductor L of inductance XL is connected in series with a    (3 marks)

bulb B and an ac source. How would brightness of the bulb

change when (i) number of turns in the inductor is reduced,

(ii) an iron rod is inserted in the inductor and (iii) a capacitor

of reactance XC = XL is inserted in series in the circuit. Justify

your answer in each case.

(i) Increases

XL =  ωL                                                                              (1/2 mark)

As number of turns decreases, L decreases, hence current through   (1/2 mark)

bulb increases. / voltage across bulb increases.                               (1/2 mark)

(ii) Decreases

Iron rod increases the inductance, which increases XL, hence            (1/2 mark)      

current through the bulb decreases / voltage across bulb decreases.  (1/2 mark)

(iii) Increases

Under this condition (XC = XL) the current through

the bulb will become maximum / increase.                                        (1/2 mark)

Difficulty Level:

Crack NEET with Online Course - Free Trial (Offer Valid Till September 22, 2019)