The light bulbs are connected in series or parallel

bulbsSerParTwo identical light bulbs are connected to identical batteries in two different ways. First they are connected in series and then in parallel. In which circuit will the bulbs shine brightly? What is the ratio of the power supplied in series to the power supplied in parallel?

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The resistance of each resistor

The total resistance of the circuit is 10 Ω. If the resistors R1 and R3 are swapped then the total resistance of the circuit will increase 100 times. If the resistors R2 and R3 are swapped then the total resistance of the circuit will increase by 0.2%.


Find the resistance of each resistor.

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The Ring


A homogeneous wire is used to make a ring with a jumper on the diameter AB. What is the percentage change in the resistance between points A and B, if the jumper is cut?
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Which of the bulbs will fuse?

DC1Two electric bulbs marked 25W – 220V and 100W – 220V are connected in series to a 440V supply. Which of the bulbs will fuse?

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The greatest possible heating power.


The four thin coiled wires have resistance of 10 ohms, 20 ohms, 30 ohms and 40 ohms. The battery has a voltage of 20 v and the internal resistance of 20 ohms. Please show how to make a heater with the greatest possible heating power.

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The semi-infinite resistance.


Determine the semi-infinite resistance between the circuit points A and B, if
resistance of each unit/link is equal to R.

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The Christmas Lights.

Lights The Christmas tree is decorated with a garland of light bulbs are connected in series. One bulb burns out and the new electric circuit is made without the burned light bulb. Is the light getting brighter or dimmer?

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