2015 - JAMB Physics Past Questions and Answers - page 1
1
The direction of the path taken by light is called
A
Locus
B
Lines
C
Ray
D
Beam
2
What is the inductance (L) of an inductor whose reactance is 1Ω at 50/ π hertz (H)?
A
100 H
B
0.01H
C
10H
D
1H
correct option: b
XL = WL = 2πFL (w = 2πf)
XL = reactance inductor (S.I unit Ω)
L = inductance (L) in Henry
XL = 1Ω, f = 50/π, L = ?
1 = 2× π × 50/π × L
1 = 100L
i.e. 100L = 1
L = 1/100
0.01H
∴ Inductance (L) of a inductor = 0.01H
Users' Answers & CommentsXL = reactance inductor (S.I unit Ω)
L = inductance (L) in Henry
XL = 1Ω, f = 50/π, L = ?
1 = 2× π × 50/π × L
1 = 100L
i.e. 100L = 1
L = 1/100
0.01H
∴ Inductance (L) of a inductor = 0.01H
3
A stroboscope can be used to make the ware appear …………..
A
Stationary
B
In motion
C
Dipper
D
Ripple
correct option: a
Stroboscope is a scientific instrument used to make a wave appears stationary when used
Users' Answers & Comments4
In an elastic collision
I. Energy is conversed
II. Energy is decreased
III. Energy is increased
IV. Linear momentum conversed
I. Energy is conversed
II. Energy is decreased
III. Energy is increased
IV. Linear momentum conversed
A
I only
B
II and IV only
C
II only
D
III only
correct option: b
In an inelastic collision, linear momentum is conserved and energy is decreased
Momentum and kinetic energy are conserved in elastic collision
Users' Answers & CommentsMomentum and kinetic energy are conserved in elastic collision
5
Body floats in fluid when its …………………
A
Displaces its own volume of the liquid (fluid)
B
Displaces its own mass of the fluid
C
Displace its own density of the fluid
D
Is no longer subjected to gravity
correct option: b
Note:The principle of floatation states that a floating body displaces its own weight of the fluid or which its float.
For object to sink weight of the object (W) > upthrust of the fluid (v) i.e. w > u
(i.e. weight of the body (or object) mass of the fluid)
Users' Answers & CommentsFor object to sink weight of the object (W) > upthrust of the fluid (v) i.e. w > u
(i.e. weight of the body (or object) mass of the fluid)
6
The general gas law can be written as
A
PV ÷ T = a constant
B
PV = a constant
C
v/t = a constant
D
p/T = a constant
correct option: a
Formula for general gas law
V × 1/T × P
N [(PV) ÷ T] = K is constant
Users' Answers & CommentsV × 1/T × P
N [(PV) ÷ T] = K is constant
7
A motor boy of a driver saw what seem to appear to be a pool of water a head of him, while his driver’s drives a new truck on a funny day. Which of the following explains his observation?
A
He saw a flying objects
B
He must be thinking of water and food
C
He was seeing the shadow of the car
D
The sun ray from the sky were passing from a hot air (layer) to cold layer
correct option: d
The appearance of pool of water on road surfaces is called MIRAGE
His observation show that light from the sun ray refracted through a layer of hot air(layer) which is closed to the ground, passes from a hot air layer to the cold layer
Users' Answers & CommentsHis observation show that light from the sun ray refracted through a layer of hot air(layer) which is closed to the ground, passes from a hot air layer to the cold layer
8
Which of the following is not luminous object?
A
The sun
B
The moon
C
light candle
D
Star
9
The resultant force of a couple is ………?
A
Infinity
B
Zero
C
One
D
Half
correct option: b
Note: moment of a couple = force × length (fL)
The tangential force is actingin an opposite direction alongside its length
i.e f1 L1 = f2L2
f2L2 − f1 L1 = 0(i.e Zero)
Users' Answers & CommentsThe tangential force is actingin an opposite direction alongside its length
i.e f1 L1 = f2L2
f2L2 − f1 L1 = 0(i.e Zero)
10
A vector quantity can only be completely described when ……… and …………are mentioned.
A
Magnitude and motion
B
Magnitude and direction
C
Distance and specified displacement
D
Moment and momentum