Home Chapter 20 Practice Questions

# Practice Questions

This activity contains 25 questions.

## The SI unit for the magnetic field is

 tesla. gauss. einstein. weber.

## Which of the following is not a unit for the magnetic field?

 tesla gauss weber weber/m2

## The red charge in the above figure is negative, the green is positive, and the blue is also negative. The magnetic field is into the page. What is the direction of the force on the red charge?

 UP (the page) DOWN LEFT RIGHT OUT (of the page) IN

## The red charge in the above figure is negative, the green is positive, and the blue is also negative. The magnetic field is into the page. What is the direction of the force on the green charge?

 UP DOWN LEFT RIGHT OUT IN

## The illustration above is the same as that in Question 3 except that the magnetic field is out of the page. What is the direction of the force on the blue charge?

 UP DOWN LEFT RIGHT OUT IN

## What is the magnitude of the force on the blue charge if its charge is 1.5 C, its speed is 25 m/s and B is .2T?

 0 N 2.5 N 5 N 7.5 N 10 N

## Both charges in the above figure are positive. What is the direction of the force on the red charge?

 UP DOWN LEFT RIGHT OUT IN

## In the preceeding question what is the direction of the force on the blue charge?

 UP DOWN LEFT RIGHT OUT IN

## If the blue charge in the previous question has a charge of 3.5 C, a speed of 30 m/s and B is 1.2 T, what is the magnitude of the magnetic force acting on it?

 89 N 100 N 129 N 200 N

## What is the direction of the magnetic field from the left wire at the right wire?

 LEFT RIGHT OUT OF THE PAGE INTO THE PAGE

## If the wires in Question 10 are separated by 15 cm and each carries a current of 10 A, what is the strength of the magnetic field from the left wire on the right wire?

 13 x 10-8 T 6.5 x 10-8 T 6.5 x 10-6 T 13 x 10-6 T

## What is the direction of the force on the right in the preceeding question?

 RIGHT LEFT OUT IN

## What is the magnitude of the force per unit length on the right wire in the preceeding question?

 1.3 x 10-4 N/m 1.3 x 10-6 N/m 6.5 x 10-5 N/m 667 N/m

## What is the direction of the magnetic field from the right wire at the left wire?

 LEFT RIGHT OUT IN

## What is the direction of the force on the left wire in the above question?

 LEFT RIGHT OUT IN

## What is the direction of the force on the wire on the right in Question 14?

 LEFT RIGHT OUT IN

## What is the direction of the force on the wire in the above figure?

 UP DOWN OUT IN

## If the wire in the preceeding question is 2 meters long and carrying a current of 50 amps in a magnetic field of 0.4 T, what is the force on it?

 40 N 28 N 19 N 10 N

## A current loop is shown edge-on in the figure. The loop carries 10 amps and has a surface area of 0.001 m2 in a magnetic field of 2 T; the torque on it (oriented as shown) is 1 Nm. What is the number of turns?

 200 100 50 10

## What is the maximum torque on the current loop in Question 19?

 0.5 Nm 1 Nm 1.5 Nm 2 Nm

## What is the magnetic dipole moment of the current loop in Question 19?

 .5 A*m2 1.0 A*m2 1.5 A*m2 2.0 A*m2

The figure above illustrates a mass spectrometer. Positive ions (q = 1.6 x 10-19 C) leave the ion source and enter a velocity selector composed of two parallel metal plates 1 cm apart with a magnet field in the green region. The voltage on the plates is adjusted until the ions go straight across. What is the direction of the magnetic field in the green area?

 UP DOWN OUT IN

## If the desired speed is 8.6 x 105 m/s and the proper voltage is 17200 volts, what is the strength of the magnetic field in the green region?

 .5 T 1 T 1.5 T 2 T

## The ions next enter the blue D-shaped area where the ions follow the semi-circular path that is shown above. What is the direction of the magnetic field in the blue area?

 UP DOWN IN OUT

## If the magnetic field, B', in the blue area is 0.5 T and the radius of the semi-circular orbit is 25 centimeters, what is the mass of the ion?

 1.16 x 10-26 kg 2.32 x 10-24 kg 2.32 x 10-26 kg 14 kg