# ONDO STATE PHYSICS JOINT EXAM ANSWERS

(1a.)* _TABULATED👇_

*under Mass*
1. Mass is the quantity of matter present in a body.
2. Mass is constant.
3. Mass is a scalar quantity.
4. The unit of mass is kg or g.
5. Mass is measured by chemical or beam balance which uses the principles of moment.

*under weight*
1. Weight occurs due to the force of gravity acting upon an object.
2. Weight varies.
3. Weight is a vector quantity.
4. The unit of weight is Newton (N).
5. Weight is measured by spring or lever balance which ones Hooke’s law

*(2)*
1. *Surface tension* is defined as the force per unit length on either side of the imaginary line drawn on the liquid surface at rest.

*OR*

*Surface Tension* is the force that causes the surface of a liquid yo act like a stretched elastic skin.

*(2b)*.
1. By adding detergent/soap to the water.
2. By adding camphor to the water.
3. By adding oil to the water.
4. By adding alcohol to the water.
5. By boiling the water.
6. By using grease.

_Choose any 3👆👆_

*(3)*
3a. Linear Expansivity is defined as the increase in length per unit rise in temperature.

*(3b)*.
1. Red hot rivets in ship.
2. Removal of tight glass stopper.
3. Bimetallic strip used in thermostat.
4. Fitting of wheels in rims.
5. Fire alarms e g. Electric bell.

Choose any 3. 👆👆

*(4)*

I. *MAXIMUM HEIGHT OF A PROJECTILE:-* This is defined as the height vertical distance reached as measured from the horizontal projection plane.

H = U² Sin² tita/2g
*Mathematically*👆

II. *HORIZONTAL RANGE OF A PROJECTILE:-* This is defined as the horizontal distance from the point of projection to the point where the projectile hits the projection plane again.

R = U² Sin2tita/g
*Mathematically* 👆

5.
The combine resistance of 3 ohm and 3 ohm in parallel
1/R=1/3+1/3=2/3
R=3/2ohm
Total resistance in the circuit=3/2+4+2
=3+8+4/2=7.5ohm

*(6)*
I=100MA =o.1A
T= 2 min = 2×60 = 120secs
Q=it
Q = 0.1 × 120
Q = 12 columbs

7.
Ī= 50MA, t=10h, v=220v P= 1, V=11,000w=11kw
Energy consumed, w=pt =11×10=110kwh
Cost of electricity =5k/kwh×110kwh
=550kobo
=N5.50k

*PART II*

*ANSWER ONLY THREE(3) QUESTIONS FROM PART II*
*(8ai)*
Wave is formed as a result of the disturbance of an elastic medium.

(8aii)
Tabulate

Light wave
(i) this are waves that do not require or need a material medium for its propagation.
(ii) They are undeflected in electric and magnetic fields.

Sound wave
(i) this are wave that require a material medium for their propagation.
(ii) They are deflected in electric and magnetic fields

(8b)
(Pick any three)
(i) Reflection.
(ii) Interference.
(iii) Refraction.
(iv) Diffraction.
(v) Polarization.

9c) i
F=mg+ma=m(g+a)
F=4(10+0.5)
F=4(10.5)
F=42N

9cii
F=mg-ma=m(g-a)
F=4(10-0.3)
F=4(9.7)
F=38.8N

9ciii
W=F=mg
=4×10=40N

*(10a)*

Machine is a device by means of which work is done more conveniently

*(10bi)*
M.A of a machine is defined as the ratio of the load to effort.

*(10bii)*

V.R of a machine is defined as the ratio of the distance moved by the effort to the distance moved by the load

(10c)*

(11ai)
Tabulate

Heat
(i) Heat is a form of energy that can be conveyed from one body to another, due to temperature difference.
(ii) The unit of measurement of heat are Fahrenheit, Celsius and ranks.
(iii) heat depends on temperature difference.

Temperature
(i) Is the degree of hotness and coldness of a body.
(ii) Temperature is measured using thermometer.
(iii) Temperature makes heat flow from one place to another

(11aii)
The Reasons

(Pick any three)
(i) Mercury does not wet glass.
(ii) Mercury responds quickly to slight change in temperature.
(iii) The liquid does not vaporise easily.
(iv) Mercury has a regular expansion.
(v) Mercury is opaque, hence it can be seen easily.

(12ai)
Movement of force often called TORQUE is the product of a force on an object and the distance from the reference point to the object.

(12aii)
Movement of couple can be define as the product of the magnitude of one of the forces and the perpendicular distance between,their lines of action.

(12bi)
(a)The algebraic sum of the moments of forces about any point in their plane must be zero

(b)For a body to,be in equilibrum under the action of parallel coplanar forces the sum of the forces in one direction (sum of upward forces) must be equal to the sum of the forces in the opposite direction (sum of downward forces).

(c)Vector sum of all forces must be zero.

(12bii)
Stable equilibrium occurs if after a body has been displayed slightly it retains to its original pattern when the displaying form has been taken

(12d)
Archimede’s Principle states: An object imposed in a fluid experiences a billiyant form that is equal in magnitude to the force of gravity on the displaced fluid.

1. Richmond Seyi August 2, 2022