P2 flashcards

• What is an induced magnet?

  A material that becomes a magnet when placed inside a magnetic field
• What is Newton’s second law?

  The acceleration of an object is proportional to the resultant force acting on the object, and inversely proportional to the mass of the object. (F=ma)
• List the uses of each part of the electromagnetic spectrum

  • Radio waves: television and radio
  • Microwaves: satellite communication and cooking food
  • Infrared: electrical heaters, cooking food and infrared cameras
  • Visible light: fibre optic communications
  • Ultraviolet: energy efficient lamps, suntanning,
  • X-rays and Gamma: medical imaging and treatments
• Name the area of force around a magnet


  Magnetic field
• List the properties of electromagnetic waves

  • All travel at 3x10^8 m/s
  • all can be transmitted, absorbed, refracted, reflected
• List the 7 sections of the electromagnetic spectrum

  Radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, gamma rays
• Describe the relationship between extension and a force applied

  Extension is directly proportional to the force applied
• Define stopping distance

  The sum of distance travelled during drivers reaction time and the distance travelled under the braking force
• What is the acceleration of a falling object near earth?

  9.8 m/s^2
• Give the unit for magnetic flux density

  Teslas
• what three types of wave can harm human body tissues?

  Ionising radiation from ultraviolet, x-rays, gamma rays
• What is a scaler quantity?

  Magnitude only
• What is a vector quantity?

  A quantity that has both magnitude and direction.
• Define transverse waves

  The oscillations are perpendicular to the direction of travel
• What is the difference between distance and displacement?

  • Distance = how far something moves (not including direction)
  • Displacement = measured in a straight line from start point to finish point and includes direction
• State three ways in which the magnetic field around an electromagnet can be increased

  • Increase the current
  • Increase the number of coils
  • Add a soft iron core
• What is meant by resultant force?

  The remaining force when forces in all directions have cancelled each other out
• What is an induced magnet?

  A material that becomes magnetized when placed in a magnetic field.
• Describe Fleming’s left-hand rule

  • The thumb, first finger and second finger are held mutually at right angles
  • THUMB - points in the direction of force
  • FIRST FINGER - points in the direction of magnetic field
  • SECOND FINGER - points in the direction of current
• What is the relationship between kinetic energy and work done by the brakes?

  The work done by the brakes is equal to the reduction in kinetic energy
• Describe the motor effect


  When a current flows through wire a magnetic field is produced around the wire. Shaping the wire into a solenoid (coil) increases the strength of the magnetic field. When the wire is placed inside a magnetic field, a force is exerted on the wire.
• State Newton’s first law

  If the resultant force on object is zero and the object is stationary, it will remain stationary but if the object is moving, it will continue to move at the same velocity.
• Define the period of a wave

  • Time taken for one wave to pass a given point
  • Period = 1 / frequency
• How are atoms affected when they absorb EM radiation?

  Electrons jump up an energy level
• Define inertia

  The tendency of objects to remain in their state of rest or uniform motion
• Why does a light ray change direction during refraction?

  Due to the change in wave speed
• How do electromagnetic waves affect a circuit?

  EM waves may induce an alternating current in a circuit
• Describe the relationship between extension and force applied

  Extension is directly proportional to the force applied
• What is meant by the conservation of momentum?

  In a closed system, the total momentum before an event is equal to the momentum after
• What is the difference between speed and velocity?

  Speed is scaler. Velocity is a vector.
• Define longitudinal waves

  The oscillations are parallel to the direction of travel