A three way light bulb has three brightness settings (low, medium, high) but only two filaments. A particular light bulb (of the said description) when connected across a 120 V line can with higher resistance burns out. The two filaments are arranged in three settings.

(i) higher resistance filament only working for 60 W

(ii) low resistance filament working for 120 W

(iii) low resistance filament working for 60 W

(iv) high resistance filament working for 120 W

(v) low and high resistance filaments in parallel for 180 W

(vi) low and high resistance filament in series for 180 W

see full answer

High-Paying Jobs That Even AI Can’t Replace — Through JEE/NEET

🎯 Hear from the experts why preparing for JEE/NEET today sets you up for future-proof, high-income careers tomorrow.

An Intiative by Sri Chaitanya

(i) , (ii) and (v) are correct

(i) , (ii) and (vi) are correct

(iii) , (iv) and (v) are correct

(iii) , (iv) and (vi) are correct

answer is A.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

Concept- An open circuit is defined to be basically a circuit where the energy is not flowing through it. When an electrical circuit is turned on, energy may flow through it, and that circuit is said to be closed. If electricity is moving from an energy source to the intended endpoint of the circuit, the circuit is said to be closed.
The 60W bulb has high resistance. If we consider switch 1 closed, the bulb with 120W power will glow instantly and if we close switch 2 then the bulb with 60W power glows. Also, if we close both the switches together then both bulbs will glow simultaneously. If the resistance is low then the 60W bulb will not glow and so the entire circuit will work only for the 120W bulb.
Hence, option 1 is correct.

Watch 3-min video & get full concept clarity