Physics

What is the unit of force?

• AJoule
• BWatt
• CNewton✓
• DPascal

Answer: Force is measured in newtons (N). 1 N is the force that accelerates 1 kg by 1 m/s².

Which equation correctly links speed, distance and time?

• Aspeed = distance × time
• Bspeed = distance ÷ time✓
• Cspeed = time ÷ distance
• Dspeed = distance + time

Answer: Speed = distance ÷ time (v = s ÷ t).

What is the resultant force on an object moving at constant velocity?

• AEqual to its weight
• BZero✓
• CIncreasing
• DEqual to its mass

Answer: At constant velocity the forces are balanced, so the resultant (net) force is zero (Newton's first law).

Which of these is the correct equation for weight?

• AW = m × g✓
• BW = m ÷ g
• CW = m + g
• DW = g ÷ m

Answer: Weight = mass × gravitational field strength (W = m g). On Earth g ≈ 9.8 N/kg.

Energy cannot be created or destroyed, only transferred or stored. This is the principle of:

• AConservation of energy✓
• BConservation of momentum
• CNewton's third law
• DOhm's law

Answer: The conservation of energy principle states energy is conserved — it changes store/form but the total stays the same.

What is the unit of electrical resistance?

• AVolt
• BAmpere
• COhm✓
• DWatt

Answer: Resistance is measured in ohms (Ω). V = I × R links voltage, current and resistance.

In a series circuit, the current is:

• ADifferent at each component
• BThe same at all points✓
• CZero
• DAlways increasing

Answer: In a series circuit there is only one path, so the current is the same everywhere.

Which type of radiation is the most penetrating?

• AAlpha
• BBeta
• CGamma✓
• DThey are equal

Answer: Gamma radiation is the most penetrating (stopped only by thick lead/concrete); alpha is the least.

What energy transfer happens in a filament lamp?

• ALight to electrical
• BElectrical to light (and heat)✓
• CChemical to kinetic
• DSound to electrical

Answer: A lamp transfers electrical energy mainly to light, with some wasted as heat (thermal) energy.

The frequency of a wave is measured in:

• AMetres
• BSeconds
• CHertz✓
• DNewtons

Answer: Frequency is the number of waves per second, measured in hertz (Hz).

Which equation gives the wave speed?

• Aspeed = frequency × wavelength✓
• Bspeed = frequency ÷ wavelength
• Cspeed = wavelength ÷ frequency
• Dspeed = frequency + wavelength

Answer: Wave speed = frequency × wavelength (v = f λ).

Sound waves are an example of which type of wave?

• ATransverse
• BLongitudinal✓
• CElectromagnetic
• DStanding only

Answer: Sound is a longitudinal wave: the particles vibrate parallel to the direction of energy transfer.