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Which statement is true for electric field lines?

KiRa [710]

The best answer is D. field lines should always be crossing each other.

8 0

3 years ago

A metallic conductor has a resistivity of 35 × 10 −6 Ω⋅m. What is the resistance of a piece that is 20 m long and has a uniform

Nitella [24]

Answer:

Therefore the resistance of the conductor is 175Ω

Explanation:

Resistance:

Resistance of a metallic conductor is directly proportional to its length(l).

Resistance of a metallic conductor is inversely proportional to its cross section area(A).

The notation sign of resistance is R.

The unit of resistance is ohm (Ω).

Therefore,

$R \propto l$

and

$R \propto \frac{1}{A}$

$\therefore R\propto \frac{l}{A}$

$\Rightarrow R=\rho \frac{l}{A}$

ρ is the proportional constant.

It is also known as resistivity of that metal.

Given ρ=35×10⁻⁶Ω-m

l= 20 m

A= 4.0×10⁻⁶m²

$\therefore R=35\times 10^{-6}\times \frac{20}{4.0\times 10^{-6}}$

=175Ω

Therefore the resistance of the conductor is 175Ω

3 0

3 years ago

7. A force of 100 N acting on a body gives it a speed of 200 m/s in 2

alekssr [168]

Answer:

Choice a. 1 kg, assuming that all other forces on the object (if any) are balanced.

Explanation:

By Newton's Second Law,

$\displaystyle a = \frac{\Sigma F}{m}$ ,

where

$a$ is the acceleration of the object in $\text{m}\cdot\text{s}^{-2}$ ,
$\Sigma F$ is the net force on the object in Newtons, and
$m$ is the mass of the object in kilograms.

As a result,

$\displaystyle m = \frac{\Sigma F}{a}$ .

Assume that all other forces on this object are balanced. The net force on the object will be $100\;\text{N}$ . The net force is constant. Acceleration should also be constant and the same as the average acceleration in the two seconds.

<h3>What is the average acceleration of this object?</h3>

$\displaystyle \begin{aligned}\text{Acceleration} &= \text{Average Acceleration}=\frac{\text{Change in Velocity}}{\text{Time Taken}}\end{aligned}$ .

$\displaystyle {a} = \frac{200\;\text{m}\cdot\text{s}^{-1}}{2\;\text{s}}=100\;\text{m}\cdot\text{s}^{-2}$ .

<h3>Apply Newton's Second Law to find the mass of the object.</h3>

$\displaystyle m = \frac{\Sigma F}{a} = \frac{100\;\text{N}}{100\;\text{m}\cdot\text{s}^{-2}} = 1\;\text{kg}$ .

6 0

3 years ago

Read 2 more answers

Suppose a shrimp has been put on the ground that has just been taken out of water.Now touch the shrimp from a distance by a stic

Alex777 [14]

Answer:

yes

Explanation:

I would say yes because it's exerting some type of force as it reacts to the stick to make it jump straight in an upwards direction

4 0

3 years ago

Read 2 more answers

When a potential difference of 10 V is placed across a certain solid cylindrical resistor, the current through it is 2 A. If the

Keith_Richards [23]

Answer:

New Resistance = 0.5556 ohm

Explanation:

Resistance = resistivity * length /area

Here since resistivity and length are constant, we only need to see how the resistance increases or decreases with change in area.

New Area = pi * (3*D)^2 / 4

Old Area = pi * D^2 / 4

The ratio of new area / old area is :

$\frac{New Area}{Old Area} = 9$

Since area increases 9 times, and it is inversely proportional to resistance:

Resistance decreases by 9 times.

So, old resistance = Voltage / Current = 10 / 2 = 5 ohm

New Resistance = 5 / 9 = 0.5556 ohm (decreases by 9 times)

8 0

3 years ago