In the circuit given below,if the bulb is to | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) The bulb is rated at $V_b = 1.5 	ext{ V}$ and $P = 0.45 	ext{ W}$.The resistance of the bulb is $R_b = \frac{V_b^2}{P} = \frac{(1.5)^2}{0.45} =

Vedclass · Accepted Answer

$1.25$

Vedclass · Answer

(A) The bulb is rated at $V_b = 1.5 	ext{ V}$ and $P = 0.45 	ext{ W}$.The resistance of the bulb is $R_b = \frac{V_b^2}{P} = \frac{(1.5)^2}{0.45} = \frac{2.25}{0.45} = 5 \Omega$.For the bulb to glow with maximum intensity,it must operate at its rated voltage of $1.5 	ext{ V}$.The current through the bulb is $i_1 = \frac{P}{V_b} = \frac{0.45}{1.5} = 0.3 	ext{ A}$.The voltage across the $3 \Omega$ resistor is $V_{3\Omega} = 6 	ext{ V} - 1.5 	ext{ V} = 4.5 	ext{ V}$.The total current in the circuit is $i = \frac{V_{3\Omega}}{3 \Omega} = \frac{4.5}{3} = 1.5 	ext{ A}$.The current through the resistor $R$ is $i - i_1 = 1.5 	ext{ A} - 0.3 	ext{ A} = 1.2 	ext{ A}$.Since the resistor $R$ is in parallel with the bulb,the voltage across $R$ is $1.5 	ext{ V}$.Therefore,$R = \frac{1.5 	ext{ V}}{1.2 	ext{ A}} = 1.25 \Omega$.

In the circuit given below,if the bulb is to glow with maximum intensity,the value of $R$ is (neglect internal resistance of the cell) (in $\Omega$)

Similar Questions

If all resistors are of $9\, \Omega$,then the reading of the ammeter is .......... $A$.

$A$ cell of emf $90\,V$ is connected across a series combination of two resistors,each of $100\,\Omega$ resistance. $A$ voltmeter of resistance $400\,\Omega$ is used to measure the potential difference across one of the resistors. The reading of the voltmeter will be $.........\,V$.

Two resistors $400 \, \Omega$ and $800 \, \Omega$ are connected in series across a $6 \, V$ battery. The potential difference measured by a voltmeter of $10 \, k \Omega$ connected across the $400 \, \Omega$ resistor is close to $.... \, V$.

What is the equivalent resistance between $A$ and $B$ in the given infinite network?

Two resistances $R_1$ and $R_2$ are made of different materials. The temperature coefficient of the material of $R_1$ is $\alpha$ and of the material of $R_2$ is $-\beta$. The resistance of the series combination of $R_1$ and $R_2$ will not change with temperature,if $R_1/R_2$ equals

Vedclass Test Series

Exam Paper Generator

Online Exam Module