# NABTEB GCE 2018 PHYSICS OBJ AND ESSAY QUESTIONS AND ANSWERS – Nov/Dec Expo

### 2018/2019 NABTEB GCE PHYSICS ESSAY AND OBJ QUESTIONS AND ANSWERS SOLUTIONS

NABTEB GCE 2018 PHYSICS THEORY AND OBJ EXPO , 2018 NABTEB GCE PHYSICS ESSAY ND OBJ EXPO , 2018/2019 NABTEB GCE PHYSICS THEORY AND OBJ SOLUTIONS, 2018 GCE PHYSICS 2018 OBJ AND THEORY ANSWERS, nov/dec 2018 NABTEB GCE PHYSICS QUESTIONS ANSWERS ,2018 NABTEB GCE PHYSICS QUESTIONS & ANSWERS ,Nov/dec 2018/2019 NABTEB GCE PHYSICS ANSWERS EXPO,2018/2018 NABTEB GCE PHYSICS ESSAY AND OBJ THEORY AND OBJ RUNZ,

Exam Time: Friday 30th November 2018
PHYSICS (Obj and Essay)
9:00am-11:30am

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

PHYSICS OBJ:
21-30: BDBCCACABC
31-40: CBACA-DDDA

(1ai)
Surface tension is defined as the unit force F per unit length acting perpendicular to the surface of a liquid. Hence surface tension T = force/length
S = F/L
OR
Surface tension is a property of a liquid which makes it behaves as though it is covered with an elastic skin.

(1aii)
Viscosity is defined as the degree if reluctance of a liquid to flow when acted upon by a force F

(1bi)
Adhesion is the force of attraction between the molecules of different substances Eg water and glass while cohesion is the force of attraction between the molecules of same substance eg
Water molecules and water molecules.

(1bii)
(i) water moving up a straw.
(ii) Water moving through a plant.
(iii) Tears moving down through tear ducts.
(iv) The movement of water through sand.
(v) The winking of paint between the hairs of a paint brush.

(1ci)
Hooke’s Law states that provided the elastic limit is not exceeded, the force of extension/compression applied on a string is directly proportional to the extension produced.
F&E = F=Ke = K = F/e
Where k is elastic constant, e is extension and F is forced applied.

(1cii)
Elasticity is the property of a material which makes it possible to return to its position after it has been extended or compressed.

==========================================

(3ai)
Lines of force (magnetic or electrified) are lines whose tangent at any point gives the direction of the field at the point.

(3aii)
(i) Lines of force emanate from a positive charge (electric field) and terminate on a negative charger.
(ii) The tangent is an electric field Line at any point gives the direction of the electric field at that point.
(iii) Two electric lines of force can not cross each other.
(iv) Lines of force cannot pass through a conductor.

(3bi)
Draw the diagram

(3bii)
(i) A gold leaf electrolyte is used to detect charges.
(ii) It is used to charge a body.
(iii) It is used to determine the charges on a body

(3ci)
Ohms law states that for ohmic conductors, other factors like temperature being constant ,the current passing through a conductor
or current is directly proportional to the potential difference applied across it’s terminals.
Hence V & I = V=IR
Where v = potential difference.
I = current
R = Resistance.

(3cii)
Resistance R = 5ohms, E = 3V
r = 0.4ohms
Draw the diagram
E = V+Ir
E = IR + Ir
E = I(R+r)
I = E/R+r = 3/5+0.4 = 3/5.4
Hence I = 0.56A, Then recall that V = IR
Hence potential difference V = 0.56×5 = 2.8V

==============================================

(4ai)
Wave particle duality is a theorem that sees wave as a particle and as well as a wave

(4aii)
Photoelectricity.

(4bi)
Radioactivity is the property of substances whereby their unstable nucleus decompose spontaneously into a more stable nucleus by emission of radiation such as alpha, gamma or beta.

(4bii)
Nuclear fission is a phenomena whereby the nucleus of an radioactive element undergoes spontaneous decay to form two or more nucleus of nearly equal mass by emission of radiation WHILE Nuclear fusion is a phenomena whereby two or more atomic nuclei are combined to form one or more different atomic nuclei and sub atomic particles like neutrons or protons, accompanied by much amount of energy.

(4ci)
Denterium and position

(4cii)
Nuclear fission.

===============================================

(5ai)
The upper fixed point or steam point is the temperature of pure boiling water of normal atmospheric pressure WHILE the lowest fixed point or ice point is the temperature of pure melting ice at normal atmospheric pressure.

(5aii)
Tita degree centigrade to Kelvin
T = (Tita + 273)k
[Pls DONT WRITE “TITA” on your paper ooo, write the tita sign. Pls view the image to understand this well]

(5bi)
Thermometric material is the material used in the thermometer whose property varies with temperature

(5bii)
(PICK FOUR)
(i) A little change in temperature should result in a proportional change in the length of the liquid.
(ii) The thermometric liquid should be coloured for easy reading.
(iii) There should be a range of temperature variation with the thermometric liquid.
(iv) The volume or length of variation should be measurable.
(v) There should be uniform variation of temperature with the thermometric liquid.
(vi) The thermometric liquid should not wet glass

(5c)
T3 = 100°c – upper fixed point
T2 = ?
T1 = lower fixed point = 0°c
L3 = 96.0mm
L2 = 33.6mm
L1 = 0.0mm

T3 – T1/T2 – T1 = L3 – L1/L2 – L1
100 – 0/T2 – 0 = 96 – 0/33.6 – 0
Cross multiply
100(33.6) = 96T2
T2 = 3360/96
T2 = 35°c

=-=-=-==-=-=-=-=completed=-==-=-=-=-=-=-=-