Two identical incandescent light bulbs are connected as shown in the Figure. When the circuit is an AC voltage source of frequency f, which of the following observations will be correct ?

Question

Two identical incandescent light bulbs are connected as shown in the Figure. When the circuit is an AC voltage source of frequency f, which of the following observations will be correct ? (A) both bulbs will glow alternatively (B) both bulbs will glow with same brightness provided frequency f =(1/2π√(1/LC)) (C) bulb b1 will light up initially and goes off, bulb b2 will be ON constantly (D) bulb b1 will blink and bulb b2 will be ON constantly

Tardigrade Admin · Accepted Answer

At resonance both bulbs will glow with same brightness. At resonance, XL=XC or 2 π f L=(1/2 π f C) or f=(1/2 π √L C)

Q. Two identical incandescent light bulbs are connected as shown in the Figure. When the circuit is an $A C$ voltage source of frequency $f$ , which of the following observations will be correct ?

both bulbs will glow alternatively

both bulbs will glow with same brightness provided frequency $f = \frac{1}{2 π ( 1/ L C )}$

bulb $b_{1}$ will light up initially and goes off, bulb $b_{2}$ will be ON constantly

bulb $b_{1}$ will blink and bulb $b_{2}$ will be ON constantly

At resonance both bulbs will glow with same brightness. At resonance, $X_{L} = X_{C}$
or $2 π f L = \frac{1}{2 π f C}$
or $f = \frac{1}{2 π L C}$

Q. Two identical incandescent light bulbs are connected as shown in the Figure. When the circuit is an AC voltage source of frequency f, which of the following observations will be correct ?

both bulbs will glow alternatively

both bulbs will glow with same brightness provided frequency f=2π(1/LC)​1​

bulb b1​ will light up initially and goes off, bulb b2​ will be ON constantly

bulb b1​ will blink and bulb b2​ will be ON constantly

At resonance both bulbs will glow with same brightness. At resonance, XL​=XC​ or 2πfL=2πfC1​ or f=2πLC​1​

Q. Two identical incandescent light bulbs are connected as shown in the Figure. When the circuit is an $A C$ voltage source of frequency $f$ , which of the following observations will be correct ?

both bulbs will glow with same brightness provided frequency $f = \frac{1}{2 π ( 1/ L C )}$

bulb $b_{1}$ will light up initially and goes off, bulb $b_{2}$ will be ON constantly

bulb $b_{1}$ will blink and bulb $b_{2}$ will be ON constantly

At resonance both bulbs will glow with same brightness. At resonance, $X_{L} = X_{C}$
or $2 π f L = \frac{1}{2 π f C}$
or $f = \frac{1}{2 π L C}$