Physics
Assertion (A): In series combination of electric bulbs, the bulb of lower power emits more light than that of the higher power.
Reason (R): The lower power bulb in series gets more current than the higher power bulb
- both A and R are true and R is the correct explanation of A
- both A and R are true and R is not the correct explanation of A
- assertion is false but reason is true
- assertion is true but reason is false
Current Electricity
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Answer
assertion is true but reason is false.
Explanation
In a series circuit, the same current flows through all the bulbs.
For bulbs of the same voltage rating,
So, the bulb of lower power rating has higher resistance.
Now, the power consumed in a series circuit is:
P=I2R
Since the current I is the same through each bulb, the bulb having greater resistance consumes more power and therefore glows brighter.
Hence, the lower power bulb emits more light than the higher power bulb in series. So, the Assertion is true.
The Reason is false because the lower power bulb does not get more current. In series combination, current is the same through every bulb.
Hence, assertion is true but reason is false.
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Assertion (A): In parallel combination of electrical appliances, total power consumption is equal to the sum of the power of individual appliances.
Reason (R): In parallel combination, the voltage across each appliance is the same.
- both A and R are true and R is the correct explanation of A
- both A and R are true and R is not the correct explanation of A
- assertion is false but reason is true
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Write an expression for the electrical energy spent in flow of current through an electrical appliance in terms of current, resistance and time.