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Biology; Chemistry; Physics: Post your doubts here!

FLRNAB

FLRNAB

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Uchiha-Sasuke said:
Lenz's law: induced current flows in a direction such that it oposes its cause
No north on left stated ...
pole on coil always develops opposite pole of magnet what is brought close ... THAT is lenz's law ... magnet moves in: north on left to oppose(repel) .. magnet moves out : south on left to oppose(attract)

they've clearly drawn that dot saying centre of circle turned by car: that's the centripetal force
Click to expand...
asadalam said:
In qs like these,the object is moving in a circle at a constant speed,so due to centripetal force the resultant will always be towards the center of the circle.
Click to expand...
The car turns in the direction of the resultant force but the centripetal force is towards the center of the circle. There are two forces on the car one from the engine and one due to friction (Centripetal). The resultant is because of the different directions of the these forces. Right? So if we use a graphical method the resultant direction should be in the direction of C?
 
Uchiha-Sasuke

Uchiha-Sasuke

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FLRNAB said:
The car turns in the direction of the resultant force but the centripetal force is towards the center of the circle. There are two forces on the car one from the engine and one due to friction (Centripetal). The resultant is because of the different directions of the these forces. Right? So if we use a graphical method the resultant direction should be in the direction of C?
Click to expand...
no that's not the case for constant speed
Constant speed = 0 acceleration = 0 forward net force ..
only centripetal force acts
funky brat said:
Plane mirror main object distance = image distance.
So explain that experiment with the mirror.
Click to expand...
I know that but I don't exactly know which lines to meet at the back of mirror for image
 
funky brat

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asadalam said:
Guys 2 Qs
If cells are connected in parallel,why isnt emf increased
and can you explain the i/v graph of thermistor and filament lamp

Awesome12 funky brat FLRNAB
Click to expand...
This is because the current can pass through only one cell at a time. I'm not sure though.
Ohm's law wala graph pata hai na? Yeh dono bhi same hain bus Thermistor ka increasing gradient hai aur filamnet lamp ka decreasing.
 
asadalam

asadalam

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funky brat said:
This is because the current can pass through only one cell at a time. I'm not sure though.
Ohm's law wala graph pata hai na? Yeh dono bhi same hain bus Thermistor ka increasing gradient hai aur filamnet lamp ka decreasing.
Click to expand...
Lekin ye graph kyn increase decrease karta hai?
 
FLRNAB

FLRNAB

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Uchiha-Sasuke said:
no that's not the case for constant speed
Constant speed = 0 acceleration = 0 forward net force ..
only centripetal force acts
Click to expand...

No that is wrong. Velocity is a vector quantity. As direction is changing velocity is changing.

Acceleration is Change in Velocity so Acceleration is not zero. If Acc is not zero then by F=ma the Resultant force is not zero.

So now back to the question? Why isn't resultant force acting in the direction of C?
 
FLRNAB

FLRNAB

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asadalam said:
Guys 2 Qs
If cells are connected in parallel,why isnt emf increased
and can you explain the i/v graph of thermistor and filament lamp

Awesome12 funky brat FLRNAB
Click to expand...
Post the graphs.

To use a hydraulic analogy, voltage is like the pressure of water in a pipe, and current is like the flow of water in pipes.

In hydraulics, pressure is the same everywhere unless something causes it to drop. That something is resistance to flow that may be due to an obstruction in the pipe, or a pipe that is too small for the wanted flow rate.

Same thing with electricity. The voltage applied to parallel branches in a circuit is the same.
The only thing that can reduce it is electrical resistance with a current flowing through the resistance.
Click to expand...
 
Muhammad_Hamza

Muhammad_Hamza

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Fate0 said:
Measure the angle of incidence at the point of incidence of both rays.
Draw a normal.
Draw the reflected ray with the angle of reflection.
When both are made, extrapolate them behind the mirror.
Where they converge, is the location of image.
Click to expand...
Is it correct......
 

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Awesome12

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asadalam said:
Guys 2 Qs
If cells are connected in parallel,why isnt emf increased
and can you explain the i/v graph of thermistor and filament lamp

Awesome12 funky brat FLRNAB
Click to expand...

For the first one, I don't really know, but it is a principle. I think that since voltage remains the same in a a parallel circuit, the emf to be provided can be divided amongst the batteries.

For the second one, about the filament lamp, it is an 'increasing at a decreasing rate' graph (V plotted on the x-axis ...)
As I increase the voltage, the current in the circuit also increases. However, the temperature increases, which causes more resistance, and ultimately leads to current decreasing



For the thermistor, as the temperature increases the resistance decreases.

When it is hot, the graph will be ' Increasing at a decreasing rate' (I plotted on x-axis)
Basically, less resistance will be occurring in the circuit, so as the current increases, the voltage will at a point become constant. There is little resistance to stop the current

When it is cold, the graph will be the opposite and ...
 
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