$R \propto \frac{1}{\tau };$ where $\tau $ $=$ Relaxation time.
When lamp is switched on, temperature of filament increase, hence $\tau $ decrease so $R$ increases
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Two identical bulbs are connected in parallel across an ideal source of emf $E$. The ammeter $A$ and voltmeter $V$ are ideal. If bulb $B_2$ gets fused, then
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