Physcis

Question 1

Describe the difference between longitudinal and transverse waves.

Answer 1

Transverse: vibrations /oscillations are perpendicular / right
angles to the direction of travel / energy transfer

Longitudinal: vibrations /oscillations are parallel to / in the
same direction as the direction of travel / energy transfer

Question 2

State the principle of superposition of waves

Answer 2

(When two or more waves meet at a point) the resultant
displacement is equal to the sum of the displacements of
the (individual) waves.

Question 3

For interference effect to be ibserved, the waves from two slits must be cohenrent. State what i meant by coherant.

Answer 3

There is a constant / fixed phase difference (between the
waves)

Question 4

sketch stress against strain graph of loading and unloading of glass

Answer 4

straingt line throug the origin

Question 5

sketch stress against strain graph of loading and unloading of rubber

Answer 5

google it

Question 6

In which region of the electromagnetic spectrum is radiation of wavelength 50um

Answer 6

Infra red

Question 7

State Newtons second law

Answer 7

the resultant force is directly proportional to the rate of change of momentum

Question 8

state 1 difference and similarity between emf and p.d

Answer 8

Similarity: They are both measured in energy per unit charge

Difference: The erergy transfered from chemical cell = emf

The energy lost to heat = p.d

Question 9

Define what is meant by stopping distance

Answer 9

The sum of the thinking distance and braking disitance

Question 10

define phase difference

Answer 10

difference in degrees/radians/angle between points on the
same wave or (similar) points on two waves

Question 11

describe the difference between stationary wave and progressive wave

Answer 11

A progressive wave transfers energy/information (in
the direction of the wave)/all points have (the same) amplitude

In a stationary wave there is no net energy transfer/energy is stored/has points which are always
zero amplitude/or points have different amplitudes

Question 12

What is meant if data is precise

Answer 12

This means that data has a small range so the data is consitent

Question 13

what is meant when datat is accurate

Answer 13

This is when your data is close to real value of something

Question 14

What is meant by the decay constant if an isotope

Answer 14

the probability of decay of a nucleus per unit time

Question 15

what is meant by induced nuclear fission

Answer 15

the splitting of a nucleus into to nuclei

Question 16

define Magnetic flux density (B)

Answer 16

stregnth of the magnetic field per unit area unit (T)

Question 17

define Magnetic flux

Answer 17

Total magnetic field lines
units (Wb)

Question 18

define magnetic flux linkage

Answer 18

Measure of total magnetic field genorated by a coil
units (Wb)

Question 19

Explain what is meant by interference

Answer 19

The superposition of coherent waves

Question 20

Materials: Define elastic

Answer 20

materials returns to original legnth with load is removed

Question 21

Materials: Define plastic

Answer 21

materials permanently deformed when load removed

Question 22

Materials: Define brittle

Answer 22

elastic behaviour ip to breaking point

Question 23

Materials: ductile

Answer 23

elastic and plastic regions before the material
breaks / able to be (permanently) deformed / stretched
/ bent without breaking

Question 24

Materials: Define ultimate tensial stress

Answer 24

maximum stress a material can withstand

Question 25

Materials: Define youngs modulus

Answer 25

Stress/strain and gradient of stress strain graph

Question 26

Kirchhoff first law

Answer 26

the sum of all currents entering a node (junction) in a circuit is equal to the sum of all currents leaving that node

Question 27

Kirchhoff second law

Answer 27

Kirchhoff’s second law states in any circuit the sum of the electromotive force is equal to the sum of the potential difference in a closed loop