Questions

Question 1

Step up transformers cause potential difference to

Answer 1

Increase

Question 2

Step up transformers cause current to

Answer 2

Decrease

Question 3

Why leave the thermometer on the object

Answer 3

To ensure the thermometer has enough time to reach the optimum temperature with the iron block as heat is transferred

Question 4

Direct potential difference

Answer 4

Constant potential difference that always flows in the same direction

Question 5

changes of particles arrangement and movement when ice melts and temperature increases

Answer 5

As the ice is warmed, motion of individual particles increase to where the bonds holding the particles locked in position in the solid begin to break and reform. This allows the particles to slide past and collide with one another as the ice is transformed to water. An increase in temperature caused the water molecules to gain energy and move more rapidly.

Question 6

Why is solar panels reliable

Answer 6

it produces energy from the sun. Since solar energy is a renewable source of energy, a solar system can produce energy as long as the sun shines

Question 7

Compare the structure of an atom of carbon-14 with the structure of an atom of carbon-12.

Answer 7

Both have the same 6 protons. Carbon 12 has 6 neutrons whereas carbon 14 has 8 neutrons. Carbon 12 is a stable isotope whereas carbon 14 is unstable and it disintegrates and goes through radioactive decay.

Question 8

What does half life mean

Answer 8

the time taken for the radioactivity of a specified isotope to fall to half its original value

Question 9

Explain which isotope would cause the biggest risk to a person’s health based only on the half-life of each isotope.

Answer 9

If a radioactive substance has a very long half-life, we know that it will remain radioactive for a very long time. The longer a substance remains radioactive, the more dangerous it is

Question 10

Describe the difference between irradiation and contamination.

Answer 10

Irradiation- Occurs when an object is exposed to a source of radiation outside the object, Doesn’t cause the object to become radioactive,Stops as soon as the source is removed

Contamination-Occurs if the radioactive source is on or in the object, A contaminated object will be radioactive for as long as the source is on or in it, It can be very difficult to remove all of the contamination

Question 11

Give one health risk to a person working close to a source of nuclear radiation.

Answer 11

Radiation sickness and death

Question 12

Explain why the worker needs to stand close to the radiation detector.

Answer 12

ensures maximum detection and accurate measurement of radiation levels, which is crucial for the safety of workers in a nuclear power station.

Question 13

Why shouldn’t you put a heavier object on a spring

Answer 13

The elastic limit of a material is the furthest point it can be stretched or deformed while being able to return to its previous shape. When an elastic object is stretched beyond its elastic limit, the object does not return to its original length or shape when the force is removed.

Question 14

Energy stores in a spring

Answer 14

Elastic potential energy is energy stored as a result of applying a force to deform an elastic object. The energy is stored until the force is removed and the object springs back to its original shape, doing work in the process.

Question 15

Why is a particle deflected in alpha model

Answer 15

The nucleus of an atom is positively charged, as are alpha particles. According to the laws of electromagnetism, like charges repel each other. So, when an alpha particle comes close to the nucleus, it experiences a strong repulsive force that changes its path. Particle A was deflected and bounced back

Question 16

Explain why the path of alpha particle B is more tightly curved than the path of alpha particle C.
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Answer 16

A stronger field will result in a more curved path, while a weaker field will result in a less curved path. Alpha particle B is in a stronger magnetic or electric field than alpha particle C.

Question 17

How is the Bohr model of the atom different from the nuclear model of the atom?

Answer 17

The Bohr model states that The atom is made up of a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus. Whereas the nuclear model states The atom is mostly empty space, with a small, dense, positively charged nucleus at the center.

Question 18

Explain how an eletron can move up and down between energy levels in an atom

Answer 18

When electrons gain or lose energy, they jump between shells as they are rotating around the nucleus. For example An electron can move from a lower energy level to a higher energy level by absorbing energy.

Question 19

Explain why the pressure increases as more air is pumped into the tyre.

Answer 19

As we pump air in, more particles are forced into a volume that stays the same and the pressure inside the tyres increases.

Question 20

the air pressure in a car tyre changes if the temperature of the air in the tyre increases. explain why

Answer 20

Pressure is a measure of how much force those atoms are exerting as they bounce off the inside of the tire. And temperature, as it turns out, is a measure of the energy of those atoms. the higher the temperature, the faster those atoms are moving, and the more force they exert as they hit the insides of the tire.

Question 21

Method about filament lamp current

Answer 21

1. Connect the circuit as shown in the first diagram.
2. Adjust the variable resistor so that the potential difference is very low or zero at the start.
3. Record the reading on the voltmeter and ammeter
4. Use the variable resistor to increase the potential difference.
5. Record the new readings on the voltmeter and ammeter.
6. Repeat steps three to four, each time increasing
   the potential difference slightly.
7. Reverse the power supply connections and repeat steps two to six.
8. Repeat the experiment but replace the fixed resistor with a bulb.
9. Plot a graph of current against potential difference for each component