Recent content by EF17xx

Thanks for your help and honesty nonetheless.

Yes ok I agree, but if the resistance is halved shouldn't the brightness increase? The answer came from the back of the book. The problem states that the magnetic field is changing however wouldn't that mean that the current keeps changing direction also. Even though that still doesn't seem...

The area got smaller (this means that flux got smaller) from the equation flux = BAcos(theta) When magnetic flux changes there is an emf induced, with a current that will oppose the change. Since flux got smaller we want it to increase right? To increase it the direction of the induced current...

Decreasing the resistance means current can flow more easily, therefore ALL current chooses path of least resistance (through the copper wire) and so none goes through light bulb 2 ?

Homework Statement The correct answer is D Homework Equations The Attempt at a Solution The current is clockwise( in the first picture at least) due to right hand rule. The magnetic flux is changing, the direction of the induced emf depends on the direction of change (increase or...

Homework Statement In an ac generator Voltage is maximum when the coil is parallel to the direction of magnetic field (B) Voltage is minimum (0) when the coil is perpendicular to the direction of magnetic field (B) I'm trying to understand why. Homework EquationsThe Attempt at a Solution A...

Thank you! I didn't think about the energy equilibrium but knowing that it makes a lot more sense.

Hi! I'm trying to understand a perfectly black body. So the definition I have found is that a black body is one that absorbs radiation of ALL wavelengths and reflects NONE. Therefore it appears black at low temperatures. And when heated it emits radiation of all wavelengths making it appear...

ok Power is Energy per time Energy is measured in Joules and 1 Joule is work done to move 1 kg 1 m. Voltage is work done to move a charge. V=W/q So is it answer C because not all of the chemical energy is transformed into thermal? Therefore it can't be 6 Joules but chemical energy is 6 Joules?

Are they the same? Sorry, I'm confused, The correct answer is answer C, it might help if you could explain why.

I know that chemical energy established the current and is transformed into thermal energy as current heats wire. P= I^2R P= VI P = V^2/R So what is the difference between power dissipated and chemical energy and thermal energy in battery and resistor?

I'm not sure because my textbook does not explain this.

Homework Statement Correct answer is Homework Equations emf = I(R + r) The Attempt at a Solution When current flows the voltage across the battery is less than the emf so it's not A I really don't understand why the answer is C because B, C, D all seem correct to me. Please help me with...

Homework Statement Homework Equations Discriminant : b^2-4ac When discriminant = 0 The function has two equal real roots When discriminant < 0 The discriminant has NO real roots When discriminant > 0 The function has 2 different real roots The Attempt at a Solution Why is it so that...

Homework Statement For accurate measurement of the fringe separation, a small as possible slit separation should be used. Homework Equations s=λD/d The Attempt at a Solution Why is this statement correct ?