Magnetic Fields and the "Slinky" coil

Tuesday, 18 September 2018

11:41 PM

 

 

 Untitled picture.png Machine generated alternative text: A student wished to use a magnetic field sensor to measure the field between the poles of a u-snaped magnet The sensor nas been calibrated, but is not properly zeroed (ie_ does not read zero when there is no magnetic field present). The sensor has what is termed a "zero error" which is a type of systematic (as opposed to random) error. To correct tor this, the student uses the sensor to measure the tield in the direction pointing from the north pole to the south pole, and then turns the sensor around to measure the field in exactly the opposite direction. T ne results are presented below Direction of Sensor Reading (mT) N tos St0N 0 291 0.092 Knowing that the magnetic field in each case is actually equal in magnitude but opposite in direction, what is the magnetic field strength beüeen the poles ottne magnet (trom N to S)? .10 Well done. One ot them is given by +8 + zero error and one is given by -a + zero error. use this to get rid of the zero error and find 8. Untitled picture.png Machine generated alternative text: A slinky coil with 110 turns is stretched out to a length ot 55.0 cm. What is the value of n, the number of turns per meter? 200 Well done. turns per meter Untitled picture.png Machine generated alternative text: Suppose that you want to design a solenoid to control magnetically the central locking system of your car doors. This needs a magnetic induction at the end ot the coil ot 0.823 T To be compact enough to tit next to the window winder mechanism, the coil can be only 3.33 cm long and 0.909 cm in diameter. The car battery can supply 7.52 A. How many turns of wire does the coil need to nave it it nas air as its core? 2900 Well done. turns What simple modification could you make to generate the required magnetic field using fewer turns and/or a lower current? Select one: Insert a material into the coil witn a higher permeability than air Insert a material into the coil witn a lower permeability than air. Increase the temperature ot the coil. Untitled picture.png Machine generated alternative text: 0-405 T K 00327m Untitled picture.png Machine generated alternative text: e—conver4 'fo m
Untitled picture.png Machine generated alternative text: Suppose that you want to design a solenoid to control magnetically the central locking system of your car doors. This needs a magnetic induction at the end ot the coil ot 0.823 T To be compact enough to tit next to the window winder mechanism, the coil can be only 3.33 cm long and 0.909 cm in diameter. The car battery can supply 7.52 A. How many turns of wire does the coil need to nave it it nas air as its core? 2900 Well done. turns What simple modification could you make to generate the required magnetic field using fewer turns and/or a lower current? Select one: Insert a material into the coil witn a higher permeability than air Insert a material into the coil witn a lower permeability than air. Increase the temperature ot the coil. Untitled picture.png Machine generated alternative text: You make 2 measurements of the Earth's magnetic field. In the horizontal plane you measure the maximum magnetic field to be 33.0 PT. In the vertical direction direction you measure it as 33.2 PT. These measurements nave already been corrected to account tor the zero error. What angle does the magnetic field make with the horizontal? 45.2 Well done. What is the magnitude ot the tield? 46.8 Untitled picture.png Machine generated alternative text: '(o mus+ be (Qr

 

 Machine generated alternative text: 0-405 T K 00327m

 

 

 Machine generated alternative text: '(o mus+ be (Qr

 

 

Created with Microsoft OneNote 2016.