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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Magnetic field due to a current in a straight wire

BiotSavartImg1A corner point makes angles θ1 and θ2 with the ends of a straight wire carrying current I. The distance of the point from the wire is a. What is the
magnetic field at the point?

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An Empire starship fires at Skywalker’s ship

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An Empire starship fires a beam of electrons at Skywalker’s ship. Each electron has an initial kinetic energy of 1.6×10−17 J. The Skywalker’s ship has been fitted out with the electrostatic shield technology for defense against electron beam weapons. The electric field of the shield points directly inward. If the electrons stop after travelling 83 m, what is the size of the electric field generated by the ship’s shield? Please ignore relativistic effects.

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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%.

3Resistors

Find the resistance of each resistor.

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The Ring

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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 path of an electron in a bubble chamber

70l9eThe diagram shows the path of an electron in a bubble chamber.

Which of the following can you deduce from the diagram?

 

(A) The electron is moving anti-clockwise.
(B) The electron is moving clockwise.
(C) The magnetic field is acting out of the page.
(D) The speed of the electron is increasing.

Source: The Student Room

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