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2 years ago

The potential difference across a resistor increases by a factor of 4. How

Physics

2 answers:

gizmo_the_mogwai [7]2 years ago

6 0

Answer: A - it increases by a factor of 4

Explanation:

Ohm's law is V = IR where V = potential difference, I = current, and R = resistance. Assuming that resistance stays constant (since the question mentioned no change in resistance), we only need to look at "V" and "I" in the equation V = IR.

"V" and "I" are directly proportional. In other words, whatever change happens to "V" will also occur to "I". Since "V" increases by a factor of 4, then "I" will also increase by a factor of 4.

You could also approach this problem by plugging in a change of 4 for the potential difference in the equation: V = I*R.

If we plug in 4V for V, we now have:

4V = I*R

Since the left side increases by a factor of 4, then the right side (only looking at current in this case) will also need to increase by a factor of 4 in order to have the right side stay equal to the left. Therefore, current will also increase by a factor of 4.

Anton [14]2 years ago

5 0

Answer:

Correct option is C it decreases by a factor of 2

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The electric current in a wire is 1.5A. How many electrons flow past a given point in a time of 2s?

kipiarov [429]

Answer:

The amount of electrons that flow in the given time is 3.0 C.

Explanation:

An electric current is defined as the ratio of the quantity of charge flowing through a conductor to the time taken.

i.e I = $\frac{Q}{t}$ ...................(1)

It is measure in Amperes and can be measured in the laboratory by the use of an ammeter.

In the given question, I = 1.5A, t = 2s, find Q.

From equation 1,

Q = I × t

= 1.5 × 2

= 3.0 Coulombs

The amount of electrons that flow in the given time is 3.0 C.

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2 years ago

An automobile with an initial speed of 4.92 m/s accelerates uniformly at the rate of 3.2 m/s2 . Find the final speed of the car

Rudik [331]

Answer:19.32 m/s

Explanation:

Given

initial speed of car(u)=4.92 m/s

acceleration(a)= $3.2 m/s^2$

Speed of car after 4.5 s

using equation of motion

v=u+at

$v=4.92+3.2\times 4.5=4.92+14.4$

v=19.32 m/s

Displacement of the car after 4.5 s

$v^2-u^2=2as$

$19.32^2-4.92^2=2\times 3.2\times s$

$349.05=2\times 3.2\times s$

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2 years ago

Joe the house painter stands on a uniform oak board weighing 600 N and held up by vertical ropes at each end. Joe has been dieti

Mamont248 [21]

Answer

given,

weight of the oak board = 600 N

Weight of Joe = 844 N

length of board = 4 m

Joe is standing at 1 m from left side

vertical wire is supporting at the end.

Assuming the system is in equilibrium

T₁ and T₂ be the tension at the ends of the wire

equating all the vertical force

T₁ + T₂ = 600 + 844

T₁ + T₂ = 1444...........(1)

taking moment about T₂

T₁ x 4 - 844 x 3 - 600 x 2 = 0

T₁ x 4 = 3732

T₁ = 933 N

from equation (1)

T₂ = 1444 - 933

T₂ = 511 N

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3 years ago

A grandfather clock has a pendulum that consists of a thin brass disk of radius r = 13.62 cm and mass 1.199 kg that is attached

Feliz [49]

Answer:

Explanation:

Expression for time period of a pendulum is as follows

T = $2\pi\sqrt{\frac{l}{g} }$

l is length of pendulum from centre of bob and g is acceleration due to gravity

Given

Time period T = 1.583

g = 9.846

Substituting the values

1.583 = $2\pi\sqrt{\frac{l}{9.846} }$

l = $\frac{(1.583)^2\times9.846}{4\times(\frac{22}{7})^2 }$

l = .6244 m

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Bumek [7]

Answer:

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Explanation:

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2 years ago

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