We know that the formula of impedance for L−R circuit, Z=R2+XL2, here, R=resistance and XL=ωL, where, L is the inductance when we insert the iron rod in inductor then the value of L increased and then the value of impedance also increased, and due to constant voltage current will be decreased across the bulb and the glow of the bulb will decrease.
NEET UG 2020 — Physics Electromagnetism
2020mcqmedium
A light bulb and an inductor coil are connected to an ac source through a key as shown in the figure below. The key is closed and after sometime an iron rod is inserted into the interior of the inductor. The glow of the light bulb
Official previous-year question
Held on 30 Apr 2020 · Verified 9 Jul 2026.
Options
- A
decreases
- B
remains unchanged
- C
will fluctuate
- D
increases
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