Assertion : An electric bulb becomes dim,when | vedclass

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

Question

(A) The electric power of a heater is significantly higher than that of a bulb. Since $P = V^2/R$,we have $R \propto 1/P$,meaning the resistance of th

Vedclass · Accepted Answer

If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.

Vedclass · Answer

(A) The electric power of a heater is significantly higher than that of a bulb. Since $P = V^2/R$,we have $R \propto 1/P$,meaning the resistance of the heater is much lower than that of the bulb.When the heater is switched on in parallel,the total current drawn from the source increases. Due to the internal resistance of the source (or line resistance),the terminal voltage across the bulb drops,causing it to become dim.As the heater coil heats up,its resistance increases due to the positive temperature coefficient of the material. Consequently,the current drawn by the heater decreases,the terminal voltage recovers,and the bulb's brightness increases (dimness decreases).

Assertion : An electric bulb becomes dim,when the electric heater in parallel circuit is switched on.
Reason : Dimness decreases after sometime.

Similar Questions

Two current elements $P$ and $Q$ have current-voltage characteristics as shown below. Which of the graphs given below best represents the current-voltage characteristics when $P$ and $Q$ are in series?

The thermo emf of a thermocouple is given by $E = aT + bT^2$,where $\frac{a}{b} = -200^{\circ}C$. If the cold junction is kept at $30^{\circ}C$,then the inversion temperature is ($\varepsilon$ in volt,$T$ in centigrade). (in $K$)

Two heating coils, one of fine wire and the other of thick wire of the same material and of the same length, are connected in series and in parallel. Which of the following statements is correct?

For a given temperature difference,which of the following pairs will generate maximum thermo $e.m.f.$?

Vedclass Test Series

Exam Paper Generator

Online Exam Module

Assertion : An electric bulb becomes dim,when the electric heater in parallel circuit is switched on.Reason : Dimness decreases after sometime.