Electricity & Energy

Question 1

graph that shows how p relates to T

Answer 1

directly proportional graph but p starts a bit up

Question 2

what is the equation combining all 3 gas laws?

Answer 2

P1 x V1 / T1 = P2 x V2 / T2

Question 3

explain what happens to the pressure of the air in a pump as its volume decreases

Answer 3

particles collide with the walls more frequently
overall force on the walls is greater
pressure increases

Question 4

V1 / T1 = V2 / T2 is ?

Answer 4

Charles Law

Question 5

P1 x V1 = P2 x V2 is ?

Answer 5

Boyles Law

Question 6

P1 / T1 = P2 / T2 is ?

Answer 6

Gay Lussac’s Law

Question 7

The voltage of a battery is

Answer 7

the number of joules of energy it gives to each coulomb of charge.

Question 8

T / F

The voltage of a battery is the number of joules of energy it gives to each coulomb of charge.

Answer 8

T

Question 9

T / F

A battery only has a voltage when it is connected in a complete circuit.

Answer 9

F

Question 10

T / F

Electrons are free to move within an insulator.

Answer 10

F

Question 11

Which of the following quantities is fully described by its magnitude?
Force; Displacement; Energy; Velocity; Acceleration

Answer 11

Energy

Question 12

A package falls vertically from a helicopter. After some time the package reaches its terminal velocity. A group of students make the following statements about the package when it reaches its terminal velocity.

Is the weight of the package less than the air resistance acting on the package?

Answer 12

No

Question 13

A package falls vertically from a helicopter. After some time the package reaches its terminal velocity. A group of students make the following statements about the package when it reaches its terminal velocity.

Are the forces acting on the package balanced?

Answer 13

Yes

Question 14

A package falls vertically from a helicopter. After some time the package reaches its terminal velocity. A group of students make the following statements about the package when it reaches its terminal velocity.

Is the package accelerating towards the ground at 9·8 m s−2?

Answer 14

No as it is at terminal velocity therefore its acceleration is 0 m s-2

Question 15

Explain why the initial temperature of the water in the kettle was likely to have been higher than a temperature that a student calculated.

Answer 15

Heat energy will have been lost to the surroundings.

Question 16

“the heat shield ablates as it melts”

Answer 16

The melting of the shield required latent heat. The ENERGY is absorbed by the heat shield than the space capsule. It needs the energy to change state.

Question 17

the theory supporting the idea of redshift is

Answer 17

the big bang theory

Question 18

explain using kinetic theory, why inflating the tyres increase the pressure inside the tyre

Answer 18

(Individual) particles collide with the (tyre) walls more frequently (than before). The (overall) force exerted on the walls is greater.

Question 19

why would a radio work in the hills but not a mobile phone.

Answer 19

mobile phones use microwaves which have a much shorter wavelength than the radio which uses radio waves. The longer the wavelength the more they diffract around the hills therefore the radio will work much better than the mobile phone.

Question 20

comment on challenges faced by an astronaut when space walking.

Answer 20

there is different pressure in different areas in space than on earth and therefore he will need a spacesuit. There is a lack of oxygen so the astronaut will need oxygen supplies. There are extreme temperatures also this will be regulated by the space suit. Cosmic radiation will be reduced by the space suit also. The astronaut may also be hit by space debris.

Question 21

what is space walking

Answer 21

any time an astronaut leaves a vehicle in space they are now space walking

Question 22

which way round do diodes or LEDs go in a circuit

Answer 22

the arrow points towards the small plate of the cell.