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1 year ago

What was the voltage on the battery for the #2 series circuit with two light bulbs?A: 4 VB: 18 VC: 4.5 VD: 9 V

1 answer:

8 0

We are given a series circuit with two light bulbs. In this case, the light bulbs act as resistors in series and the total resistance is:

$R_t=R_1+R_2$

That is the sum of all the resistances in series in the circuit. To determine the voltage we can use Ohm's law:

$V=IR$

Where "R" is the total resistance and "I" is the current in the circuit. Replacing we get:

$V=I(R_1+R_2)$

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If a voltmeter has a less than ideal resistance, say 1 MΩ, and is used to measure the voltage across a resistor of a comparable

Naddik [55]

Answer:

As the difference between the resistance of voltmeter and the resistance being measured gets reduced the error in the reading of the voltmeter gets increased.

Explanation:

An ideal voltmeter has infinite parallel resistance and because of this it doesn't draw any current from the circuit of measurement which means it will measure the exact voltage across the elements.

But practically speaking, a real voltmeter doesn't has infinite resistance therefore, all the practical voltmeters face loading effect to some extent.

As the difference between the resistance of voltmeter and the resistance being measured gets reduced the error in the reading of the voltmeter gets increased. This is why we want to have a greater value of voltmeter resistance, ideally infinite so that the corresponding error is minimized.

Lets consider the given scenario,

A voltmeter has 1 MΩ parallel resistance and the resistance of of measuring element is 500 kΩ or 0.5 MΩ

lets suppose the supplied voltage is 1 V.

First lets assume that the voltmeter is ideal and it has infinite resistance, so in this case voltmeter will measure a voltage of 1 V across the 0.5 MΩ resistor.

Now consider the loading effect, when we connect the voltmeter across the 0.5 MΩ resistor they both become parallel so the resistance is

R = (1*0.5)/(1+0.5)

R = 0.33 MΩ

As you can see the voltmeter will see a reduced resistance and the corresponding voltage also reduces because resistance and voltage are directly proportional.

Therefore, it is preferred to have a very high parallel resistance of the voltmeter.

8 0

3 years ago

What is the name of the phenomenon that causes observed light from a star to change its wavelength?

blagie [28]

Answer: This is called the Doppler effect, where waves shift frequency and wavelength as the source travels towards you (higher frequency, shorter wavelength) or away from you (lower frequency, longer wavelength)

Explanation:

hoped this helped have a good day :)

5 0

3 years ago

Does the lattice energy of an ionic solid increase or decrease as the charges or sizes of the ions increase?

alexandr1967 [171]

Answer:

Explanation:

Lattice energy is the energy required to separate one mole of an ionic solid compound into its components gaseous cations and anions.

Due to increase in size of the ions, the lattice energy decreases while the lattice energy increases as the charge of the ions increases.

When the size increase, the distance between the nuclei also increase leading a decrease the force of attraction between the nuclei

7 0

3 years ago

You kick a soccer ball of mass 0.41 kg. the ball leaves your foot with an initial speed of 23 m/s. (a what is the magnitude of t

svetoff [14.1K]

Impulse describes the change of momentum. Since we don't know the momentum of the soccer ball before the hit, this question is hard to answer. If you assume the momentum of the ball before the hit was p = 0, then the change in momentum is just Δp = Impulse = mv.

7 0

3 years ago

Read 2 more answers

Jenny was applying her makeup when she drove into the student parking lot last Friday morning . Unaware that Cheryl was stopped

Akimi4 [234]

Answer: F = 102141N

Explanation: Newton's 2nd Law states that a force can change the motion of a body. The relation is given by

F = m.a

whose units are:

[F] = N

[m] = kg

[a] = m/s²

Jenny's car, at the moment of the break, had acceleration:

$a=\frac{\Delta v}{\Delta t}$

$a=\frac{11}{0.14}$

a = 78.57 m/s²

Then, Force is

F = 1300*78.57

F = 102141 N

Jenny's car experienced a force of magnitude 102141N.

6 0

2 years ago