7.2 Electric fields

• Electric field strength is measured in N/C
• The units of electric field strength are N/C
• The electrostatic constant $k$ has a value of approximately $8.99 \times 10^{9}$
• The electric field strength depends on distance in an inversely proportional manner to r^{2}
• The electrostatic constant k is approximately $8.99 \times 10^{9}$
• Match the property with the correct field:

  Electrostatic force ↔️ Electric Field

  Gravitational force ↔️ Gravitational Field
• The unit of electric field strength is N/C
• Electric field strength is inversely proportional to the square of the distance from the charge.


  True
• Electric field lines originate from positive charges and terminate on negative charges.


  True
• Electric field lines move from positive to negative
• What is the formula for the electric field strength in a uniform field between parallel plates?

  $E =$$\frac{V}{d}$
• What does the variable 'd' represent in the formula for electric field strength between parallel plates?

  Distance between plates
• What is 'E_net' in the formula for the superposition principle?

  Net electric field
• The superposition principle simplifies the calculation of net electric fields by summing individual contributions.

  True
• The electric field points in the direction of increasing electric potential.

  False
• The direction of the electric field is the direction of force on a positive test charge.


  True
• What is the formula for the electric field strength due to a point charge Q at a distance r?

  $E =$$\frac{kQ}{r^{2}}$
• Match the property with its field:

  Charged particle ↔️ Electric Field

  Point mass ↔️ Gravitational Field
• What is the origin of electric field lines?

  Positive charges
• Electric field lines always start on negative charges.

  False
• Gravitational field lines originate from positive charges.

  False
• Match the superposition properties with their descriptions:

  Electric Fields ↔️ Fields due to charges

  Gravitational Fields ↔️ Fields due to masses

  Operation ↔️ Vector addition
• The total electric field midway between a +2C and -3C charge is zero.

  False
• What is an electric field defined as?

  Region of space with force
• What is the formula for electric field strength in terms of force and charge?

  $E =$$\frac{F}{q}$
• What is the formula for the electric field strength around a point charge?

  $E =$$\frac{kQ}{r^{2}}$
• Match the field formula with the type of field:

  E = \frac{kQ}{r^{2}}</latex> ↔️ Electric Field

  $g =$$\frac{GM}{r^{2}}$ ↔️ Gravitational Field
• What is the formula for electric field strength around a point charge?

  $E =$$\frac{kQ}{r^{2}}$
• An electric field is quantified by the electric field strength
• What is the formula for electric field strength in terms of force and charge?

  $E =$$\frac{F}{q}$
• Steps to calculate electric field strength around a point charge:

  1️⃣ Identify the charge Q

  2️⃣ Identify the distance r

  3️⃣ Use the formula $E =$$\frac{kQ}{r^{2}}$

  4️⃣ Calculate the value of E
• Match the field property with the correct type of field:

  Charge Q ↔️ Electric Field

  Mass M ↔️ Gravitational Field
• What is the formula for electric field strength between parallel plates?

  $E =$$\frac{V}{d}$
• What is the formula for the superposition principle of electric fields?

  $E_{net} =$$E_{1} +$$E_{2} +$$E_{3} +$$... +$$E_{n}$
• The potential difference between parallel plates is measured in volts.


  True
• The superposition principle applies only to point charges.

  False
• What is the formula for the net electric field at a point between two point charges Q₁ and Q₂ separated by a distance r?

  $E_{net} =$$\frac{kQ_{1}}{r^{2}} +$$\frac{kQ_{2}}{r^{2}}$
• The unit of electric potential is the volt
• The electric field strength at a point is the force per unit positive charge
• Electric field strength is measured in N/C