Electric Circuits Answers

what happens to drift velocity when wire is heated?

element of a 500w electric iron is designed for use on a 200v supply. what value of resistance is needed to be connected in series inorder that iron can be operated from a 240v supply?

A runner is practicing on a circular track that is 415 m in circumference. From the point farthest to the east on the track, he starts off running due south and follows the track as it curves around toward the west.
(a) If he runs halfway around the track and stops at the farthest western point of the track, what is the distance he traveled?

An object moving at a constant speed of 100 meters in 25 sec.
What is the speed of the object?
How far doed the object move in 20 sec?
How longwill it take the object to move 80m?

An object of mass 5 kg is secured by a string and set to rotate round a vertical circular path of 2 m radius . when the object is at the lowest possition its tangential speed is 6 m/s , calculate the tension in the string.

would there be change in the reading of ammeter if we place the ammeter before or after a resistor?

Joe was debugging part of an experimental apparatus, probing around with his voltmeter. Part of the apparatus had two obvious resistors in series with an unknown element, as shown in the diagram below:

The unknown element is hard to reach, so Joe put the negative (black) probe of his voltmeter at the interconnection of the two obvious resistors and then put the positive (red) probe at the other end of each resistor, measuring v1=1.4V and v2=0.9V.
What is the voltage (in Volts) v3 measured across the unknown element?

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S1E6: KVL

In the circuit shown there are four unknown elements and an independent voltage source.

The strength of the source V is given. Also, there are two known branch voltages: we know v1 and v2.
In terms of the known voltages, write an algebraic expression for the branch voltage v3. Be careful, algebraic expressions are case sensitive.

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Write an algebraic expression for the branch voltage v4:

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Write an algebraic expression for the branch voltage v5:

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S1E7: KCL-0

While further poking around in his experiment, Joe found an exposed interconnect. It connected the positive output of the 5V power supply, a 3.3Ω resistor, and two unknown 2-terminal elements, as shown:

He couldn't trace where the other ends of the elements went. However, he had a nifty (very expensive!) Hall-effect clamp-on ammeter that he used to measure the three of the four currents entering the elements. He didn't have enough space to measure the current entering the fourth element. He found that i1=−0.7A, i3=3.0A, i4=1.3A.
What was the current (in Amperes) i2 into the fourth element?

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Joe managed to get his ammeter probe around a wire and measured i5. What current (in Amperes) did he measure?

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S1E8: KCL

In the circuit shown there are six unknown elements.

By measurements we have values for three of the branch currents: i1, i2, and i3.
In terms of the known currents, write an algebraic expression for the current i4?

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Write an algebraic expression for the current i5?

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Write an algebraic expression for the current i6?

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10. A hockey slap-shot is hit at the goal, 30 meters away. The puck, which weighs 0.250 kg, covers that distance in 0.38 seconds. How much momentum does the puck have?