Assertion : An electric bulb becomes dim, when the electric heater in parallel circuit is switched on.
Reason : Dimness decreases after sometime.
A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.
AIIMS 2008, Easy
Download our app for free and get started
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
b The electric power of a heater is more than that of a bulb. As $P\, \propto \,\frac{1}{R}$, the resistance of heater is less than that of the electric bulb. When a heater connected in parallel to the bulb is switched on, it draws more current due to its lesser resistance, consequently, the current through the bulb decreases and so it becomes dim. When the heater coil becomes sufficient hot, its resistance becomes more and hence it draws a little lesser current. Consequently, the current through the electric bulb recovers.
Download our app
and get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
A battery of $6\, volts$ is connected to the terminals of a three meter long wire of uniform thickness and resistance of the order of $100\,\Omega $. The difference of potential between two points separated by $50\,cm$ on the wire will be .......... $V$
If $n,\,e,\,\tau $ and $m$ respectively represent the density, charge relaxation time and mass of the electron, then the resistance of a wire of length $l$ and area of cross-section $A$ will be
In the given circuit the internal resistance of the $18\,V$ cell is negligible. If $R_1 = 400 \,\Omega ,\,R_3 = 100\,\Omega $ and $R_4 = 500\,\Omega $ and the reading of an ideal voltmeter across $R_4$ is $5\,V,$ then the value of $R_2$ will be ........... $\Omega$
A cell of $e.m.f.$ $1.5\,V$ having a finite internal resistance is connected to a load resistance of $2\,\Omega $. For maximum power transfer the internal resistance of the cell should be ............. $ohm$