physics practicals

• What are the three types of variables in practical investigations?

  Independent, dependent, and controlled variables
• Why is it important to state the equipment used for measurements?

  It ensures clarity and accuracy in results
• How can you reduce parallax error when measuring?

  Align your eye with the measurement scale
• What is the benefit of taking multiple measurements?

  It allows calculation of a mean for accuracy
• What is a recommended format for writing answers in practicals?

  Bullet point format
• What should you avoid when writing practical answers?

  Using informal or abbreviated language
• What is specific heat capacity (SHC)?

  • Energy needed to raise 1 kg by 1°C
  • Unique to each material or substance
• How can SHC be determined for water or metals?

  By using an electrical heater in a beaker
• What should be measured every 20 seconds during the SHC experiment?

  The temperature of the water or metal
• How do you calculate the power supplied to the heater?

  Using an ammeter and voltmeter readings
• What is the equation for specific heat capacity?

  SHC = energy / (mass × temperature change)
• How can energy supplied to the block be calculated?

  Multiply power by time in seconds
• What does plotting temperature against energy show in the SHC experiment?

  It shows a linear relationship
• What is the relationship between wire length and resistance?

  Resistance is directly proportional to length
• What type of wire is used in the resistance experiment?

  Constantan wire
• How is resistance calculated in the wire experiment?

  Resistance = voltage / current
• What happens to the current in a fixed resistor when the PD varies?

  The current changes proportionally
• What type of graph is produced with a filament bulb?

  A curve showing non-ohmic behavior
• Why does resistance increase in a filament bulb at higher currents?

  Temperature increases causing more collisions
• What is the behavior of a diode in terms of current flow?

  Allows current in one direction only
• How is density calculated for regular objects?

  Density = mass / volume
• How do you find the volume of an irregular object?

  Using water displacement method
• What is the density of pure water?

  1 g/cm³
• How can the spring constant be determined?

  By plotting force against extension
• What is the formula for Hooke's Law?

  F = k × x
• What does a straight line through the origin indicate in a spring experiment?

  A directly proportional relationship
• How can Newton's Second Law be verified?

  By measuring acceleration with a trolley
• What is the relationship between force and acceleration?

  Force = mass × acceleration
• How can wave speed be calculated?

  Using the equation V = F × λ
• What is the purpose of a ripple tank in wave experiments?

  To visualize wave patterns and measure wavelength
• How can the refractive index be determined?

  By measuring angles of incidence and refraction
• What does a higher refractive index indicate?

  Light travels slower in that material
• What are the key properties of infrared radiation absorption experiments?

  • Matte black surfaces emit and absorb best
  • Shiny surfaces reflect and absorb poorly
• What is the procedure for insulation experiments?

  • Wrap beakers of hot water in insulation
  • Record temperature drop over time
• What is the significance of using a strobe light in wave experiments?

  • It makes waves appear stationary for measurement
  • Helps in accurately determining wavelength
• What is the relationship between frequency and wavelength in waves?

  • As frequency increases, wavelength decreases
  • Wave speed remains constant unless medium changes
• What is the importance of measuring angles in refraction experiments?

  • To calculate the refractive index accurately
  • Helps understand light behavior in different materials