OCR GCSE Combined Science A (Gateway) Physics Paper 12 Higher November 2021 question paper J250/12

Which row in the table explains why a safety belt is a safety feature in a car?

Which factor increases both thinking distance and braking distance?

A Drinking alcohol

B Icy roads

C Increasing speed

D Worn tyres

Some waves are transverse. Some waves are longitudinal.

Which row in the table is correct?

Which property is the same for all electromagnetic waves in space?

A Frequency

B Time period

C Velocity

D Wavelength

A 6 V battery transfers 1860 J of energy.

Calculate the charge transferred by the battery.

Use the equation: energy transferred = charge × potential difference

A 0.31 C

B 11.16 C

C 310 C

D 11 160 C

This is a model of energy levels inside a hydrogen atom.

Which electron movement, A, B, C or D, shows ionisation?

An 800 W microwave oven is used for 30 minutes.

What is the energy transferred in kWh?

Use the equation: energy transferred = power × time

A 0.4 kWh

B 24 kWh

C 240 kWh

D 400 kWh

Radio waves are electromagnetic waves and are used for communications.

Suggest why gamma rays are not used for communications.

Name one other electromagnetic wave that is used for communications.

State one use of this electromagnetic wave in communications.

A TV transmitter emits electromagnetic waves with different frequencies.

Table 11.1 gives information about the waves emitted.

Using data from Table 11.1 describe the relationship between frequency and wavelength.

How many significant figures are used in each value in Table 11.1 ?

Calculate the speed of the wave ARQ B.

Use the equation: wave speed = frequency × wavelength

Speed =........ m / s

A TV transmitter has a useful output energy transfer of 100 kJ in 1 second.

The input energy is 250 kJ in 1 second.

Calculate the efficiency of the TV transmitter.

12* Two students do an experiment to calculate their reaction times. They use a 30 cm ruler.

Describe, in detail, a suitable method the students can use to calculate reaction time using the ruler.

In your answer, include:

• Equations the students can use to calculate reaction time.

• How the students can obtain accurate and precise results.

State the law of conservation of energy.

Fig. 13.1 shows the experiment a student sets up on the ground to investigate energy stores.

• The student places a magnet at the top of a small ramp.

• They place a small iron ball at the bottom of the ramp.

• The iron ball is attracted up the ramp.

• The iron ball ‘sticks’ to the magnet.

The table describes how the energy stores change.

Complete the table using the words MAXIMUM and MINIMUM.

The mass of the marble is 0.003 kg.

The kinetic energy of the marble is 0.024 J at the bottom of the ramp.

Calculate the speed of the marble at the bottom of the ramp.

Use the equation: kinetic energy = 0.5 × mass × (speed)²

Speed =........ m / s

The marble rolls to a stop on the horizontal rough surface after it leaves the ramp.

Explain what happens to the kinetic energy store of the marble.

X and Y are radioactive isotopes. They emit either alpha particles or beta particles.

Complete Table 14.1 to show what happens to a nucleus of an atom when an alpha particle or a beta particle is emitted.

A scientist measures the half-life of isotope X.

They measure the half-life three times.

Why do they get a slightly different result each time?

After 18 days, the ratio of the activity of X to the initial activity of X is 1:4.

Calculate the half-life of isotope X.

Isotope X only gives out beta particles. Isotope Y only gives out alpha particles.

The scientist measures the activity of one of the isotopes using a Geiger counter.

They then place a material between the isotope and the Geiger counter and record the reading.

Table 14.2 shows their results:

Which isotope are they using?

Give two reasons for your answer.

The scientist accidentally places isotope X close to isotope Y.

Explain why isotope Y is irradiated, but not contaminated, by isotope X.

Nuclear power is non-renewable and the plants can produce nuclear waste.

Suggest two reasons why some countries still use nuclear power.

Two students are making waves using a dripping tap.

The water droplets create waves in the water in a bowl.

Describe the change in energy stores as a water droplet

• falls from the tap:........

• lands in the water in the bowl:........

The students count the number of droplets hitting the water in the bowl.

In 20 seconds, 5 droplets hit the water in the bowl.

Calculate the frequency of the waves produced.

How can the students tell that the water waves travel but the water does not?

One of the students says, ‘the temperature of the water in the bowl increases when the water drips into it’.

• 1 droplet of water transfers 5.04 × 10⁻⁴ J of energy as it lands in the bowl.

• The bowl contains 3 kg of water.

• The specific heat capacity of water is 4200 J / kg °C.

Calculate the temperature rise of the water in the bowl when 1 droplet of water lands in it.

Use an equation from the Data Sheet to help you.

In 1847, James Joule did experiments at the bottom of a waterfall.

He was unable to measure the temperature rise of the water.

Suggest two reasons why.