Physics P1 exam questions

Which energy store is associated with a stretched elastic band?

Elastic potential

What is the unit of power?

Watts

Describe how to determine the specific heat capacity of a metal block using a heater, thermometer, and timer. (6)

• Place heater and thermometer in metal block (1)

• Insulate block to reduce energy loss (1)

• Measure temperature and record every minute (1)

• Use E = P × t to find energy supplied (1)

• Use c = E / (m × ΔT) (1)

• Safety: handle hot equipment with care (1)

A motor transfers 400 J of energy in 5 seconds. Calculate the power.

Power = 400 ÷ 5 = 80 W

Describe one way to improve the efficiency of a mechanical device.

Lubricate moving parts / reduce air resistance (1); reduces wasted energy (1)

Explain how insulation reduces energy loss in a house.

Insulation prevents heat escaping (1); keeps house warm, reducing energy demand (1)

Draw a simple circuit with a cell, switch, resistor, and voltmeter.

Diagram includes: cell, switch, resistor, voltmeter parallel to resistor (2)

What is the relationship between current, voltage, and resistance? Write the equation.

V = I × R (1)

A circuit has a 12 V supply and 4 ohms resistance. Calculate the current.

I = 12 ÷ 4 = 3 A (3)

Name the three types of nuclear radiation.

Alpha, beta, gamma (1)

Which type is the most penetrating?

Gamma

Describe how radiation is used in medicine and explain the risks.

Used in radiotherapy / tracers / sterilisation (1); kills cells (1); can cause mutations / cancer (1); benefits must outweigh risks (1)

A 3 kg block is lifted 5 m in 4 seconds.

a) Calculate the gravitational potential energy gained by the block. (g = 9.8 N/kg) (2)

Ep = m × g × h = 3 × 9.8 × 5 = 147 J (2)

b) Calculate the power of the lift. (2)

Power = 147 ÷ 4 = 36.75 W (2)

c) Explain why not all the energy transferred by the motor is useful. (2)

Some energy is lost as heat due to friction/resistance (1); system is not 100% efficient (1)

Describe how to measure the specific heat capacity of a material using electrical heating. Include equations and measurements. (4)

• Measure mass of block (1)

• Insert heater and thermometer (1)

• Measure temp change over time (1)

• Use E = P × t and c = E ÷ (m × ΔT) (1)
  b)

• Use insulation to reduce heat loss (1); use lid or delay measurements for stable readings (1)

Explain two ways to reduce energy losses in this practical. (2)

Use insulation to reduce heat loss (1); use lid or delay measurements for stable readings (1)

Compare the current and potential difference in series and parallel circuits. (3)

• Series: current same, voltage shared (1)

• Parallel: current shared, voltage same (1)

• Resistors add in series but not in parallel (1)

b) A 6 V battery is connected to two identical resistors in series. Each resistor is 3 Ω. Calculate the total current. (3)

Total resistance = 3 + 3 = 6 Ω (1)
I = V ÷ R = 6 ÷ 6 = 1 A (2)

A factory uses a gamma source to monitor the thickness of aluminium foil. Explain why gamma is used. (2)

Gamma is highly penetrating; passes through foil (1); detected on other side (1)

Describe two safety precautions for workers. (2)

Use shielding / lead-lined equipment (1); keep distance or limit exposure time (1)

Explain the potential long-term health risks of exposure to ionising radiation. (2)

Radiation can ionise DNA (1); increases risk of mutations/cancer (1)