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**A-Level** **Physics**** Question Analysis Topic: Physics - Circuit**

**Exam Question:**

1) Two electric bulbs P and Q have their resistances in the ratio of 1:2. They are connected in series across a battery. Find the ratio of the power dissipation in these bulbs.

**Answer:**

For A-Level Physics, you should know:

1) We know that the resistance of the bulbs are in the** ratio of 1:2 (P:Q)**.

We also know that the formula for power is **Power = I**^{2}**R**

By using the ratio given:**P**_{P}**/P**_{Q}** = I**^{2}**R**_{P}**/I**^{2}**R**_{Q}

The bulbs are connected in **series**. Thus, current flowing in them should be the **same** **i.e., I**_{P}** = I**_{Q}** = I**

Utilising the ratio again, we have:**P**_{P}**/P**_{Q}** = R**_{P}**/R**_{Q}** = 1/2**

Work hard for your A-Level Physics examination!

End of analysis. Great!