SP025 Chapter 4 Magnetic Field (C1&C2)

The magnetic field lines always begin from

• N-pole and end on S-pole

• S-pole and end on N-pole

• Start from the middle and end at N-pole

• Start from the middle and end at S-pole

The magnetic field is the strongest at

• middle of the magnet

• north pole

• south pole

• both poles

The strength of magnetic field around a current carrying conductor is

• Inversely proportional to the  current but directly proportional to the square of the distance from wire

• Directly proportional to the current    and inversely proportional to the distance from wire.

• Directly proportional to the distance and inversely proportional to the current.

• Directly proportional to the current and inversely proportional to the square of distance from wire

Which of the following is NOT effect the magnitude of magnetic field intensity of the circular coil?

• Diameter of circular coil

• Current flow in the coil

• Magnetic poles

• Number of coil

Describe the path of a charge moving at right angles in a uniform magnetic field

• straight 

• circular

• parabola

• parabola

A positive charge moves in parallel to a current carrying wire. What is the direction of the magnetic force on the charge?

• left

• right

• To the bottom of the page.

• To the top of the page.

A wire carrying a current in the direction shown is placed at right angles to a uniform magnetic field, B. In which direction does the magnetic force act on the wire?

• Out of the paper

• Into the paper

•  Downwards

• Upwards

Force on a wire inside magnetic field increases when

• the current is increased

• strength of the magnetic field increases

• length of wire increased

• all of the above

A beam of electrons is allowed to pass through the velocity selector in a Bainbridge spectrometer. The function of velocity selector is

• to accelerate the electrons

• to decelerate the electrons

• allow electrons of a certain speed to move through the region

• to focus the electrons onto the screen

An ion beam enters peprpendicularly into an area of magnetic field. Which of the following equation describes the motion of the ion beam.