You buy a 75-W lightbulb in Europe, where electricity is delivered to home at 240 V

You buy a 75-W lightbulb in Europe, where electricity is delivered to home at 240 V. If you use the lightbulb in the United States at120 V (assume its resistance does not change). how bright will it be relative to 75-W 120-V Bulbs? [ Hint: assume roughly that brightness is proportional to power consumed]

Expert Solution

resistance of bulb is found by:

\(\mathrm{P}=\mathrm{V}^{2} / \mathrm{R} \quad 75=240^{2} / \mathrm{R} \quad \mathrm{R}=768 \mathrm{ohms}\)

Now find the power it uses when plugged into \(120 \mathrm{~V}\) :

\(\mathrm{P}=\mathrm{V}^{2} / \mathrm{R}=120^{2} / 768=18.75 \mathrm{Watts}\)

So compared to a 75 watt bulb is it is only:

18.75 / 75 = 1/4 as bright

Dr. OWL answered 3 years ago

A 1.0-m lamp cord leads from the 110-V outlet to a lamp having a 75-W lightbulb....

A 1.0-m lamp cord leads from the 110-V outlet to a lamp having a 75-W lightbulb. The cord consists of two insulated parallel wires 5.0 mm apart and held together by the insulation. One wire carries the current into the bulb, and the other carries it out. 4)Compare the field between 1.0 mm from one of the wires in the same plane in which the two wires lie with Earth’s magnetic field? (Express your answer to two significant figures.)

A 2400-W oven is connected to a 240-V source. 1. What is the resistance of the...

A 2400-W oven is connected to a 240-V source. 1. What is the resistance of the oven? Express your answer to two significant figures and include the appropriate units. 2. How long will it take to bring 110 mL of 25 ∘C water to 100∘C assuming 65 % efficiency? The specific heat capacity of water is 4186 J/(kg⋅∘C). Express your answer using two significant figures. 3. How much will this cost at 12 cents/kWh? Express your answer using two significant...

You have a 40- lightbulb and a 100-W bulb. 1. Find the resistances of the 40-W...

You have a 40- lightbulb and a 100-W bulb. 1. Find the resistances of the 40-W bulb. Take that ΔV = 120 V. 2. Find the resistances of the 100-W bulb. Take that ΔV = 120 V. 3. If the two bulbs are connected separately, which of them will be brighter? 4. If the two bulbs are connected in series to a battery source, which of them will be brighter? 5. If the two bulbs are connected in parallel to...

A patient is supplementing their potassium intake by taking 75 mL of a 3.5% (w/v) potassium...

A patient is supplementing their potassium intake by taking 75 mL of a 3.5% (w/v) potassium bicarbonate solution daily. How many milliequivalents of potassium ion is the patient consuming daily? KHCO3 MW 100 K+ MW 39 HCO3- MW 61

2 Let u,v, and w be vectors, where u=(1,2,3,-1), v=(2,3,1,5) and w=(3,5,4,4). 2.1 Construct a basis...

2 Let u,v, and w be vectors, where u=(1,2,3,-1), v=(2,3,1,5) and w=(3,5,4,4). 2.1 Construct a basis for the vector space spanned by u, v and w. 2.2 Show that c=(1,3,2,1) is not in the vector space spanned by the above vectors u,v and w. 2.3 Show that d=(4,9,17,-11) is in the vector space spanned by the above vectors u,v and w, by expressing d as a linear combination of u,v and w.

True/False Question: If sppan{u,v}=W where u not equal to v. Then dim(W)=2. Answer: False Reasoning let...

True/False Question: If sppan{u,v}=W where u not equal to v. Then dim(W)=2. Answer: False Reasoning let u=1, v=2 then span(1,2}=R but dim(R)=1 not 2. I know the answer is false. please tell me whether my reasoning is correct.

In preparing an IV infusion containing sodium bicarbonate, 50 mL of a 75% (w/v) sodium bicarbonate...

In preparing an IV infusion containing sodium bicarbonate, 50 mL of a 75% (w/v) sodium bicarbonate (z=84) injection were added to 500 mL of D5W. How many mEq of sodium are represented in the total infusion (round to one decimal)

A North American tourist takes his 25.0-W, 120-V AC razor to Europe, finds a special plug...

A North American tourist takes his 25.0-W, 120-V AC razor to Europe, finds a special plug adapter, and plugs it into 240 V AC. Assuming constant resistance, what power does the razor consume as it is ruined?

Let X ∈ L(U, V ) and Y ∈ L(V, W). You may assume that V...

Let X ∈ L(U, V ) and Y ∈ L(V, W). You may assume that V is finite-dimensional. 1)Prove that dim(range Y) ≤ min(dim V, dim W). Explain the corresponding result for matrices in terms of rank 2) If dim(range Y) = dim V, what can you conclude of Y? Give some explanation 3) If dim(range Y) = dim W, what can you conclude of Y? Give some explanation

If you are given that y = f(x, v, w) = 2x -3 w + 5v;...

If you are given that y = f(x, v, w) = 2x -3 w + 5v; if you are also told the values of w = 5 and v = 10 a) Find an expression for f(x) = y in terms of x (i.e. plug in for w and v and reduce the equation b) Plot your solution to the right c) If you are told that x changes from 4 to 6, illustrate and explain what happens in your...

Question