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Magnetic effect of electric current and light

Magnetic effect of electric current and light

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Question 1
The space surrounding a magnet where a magnetic force is experienced is called _______
A
magnetic field
B
magnetic lines of force
C
magnetic poles
D
magnetic induction
Question 2
The path taken by the north pole is called _________
A
magnetic force
B
magnetic field
C
magnetic lines of force
D
magnetic intensity
Question 3
The characteristics of magnetic lines of forces is ________
A
field lines emerges from north pole and merge at south pole
B
closed curves
C
never cross each other
D
all the above
Question 4
When current flows in a wire, it creates_______
A
an electric field outside
B
magnetic field around it
C
both the electric and magnetic fields
D
neither the electric nor the magnetic fields
Question 5
What is the direction of magnetic needle placed near the conductor in which current flows in clockwise direction?
A
move towards east
B
move towards west
C
No movement
D
Move opposite i.e. south to north
Question 6
which of the following correctly describes the magnetic field near a long straight wire?
A
The field consists of straight lines perpendicular to the wire
B
The field consists of straight lines parallel to the wire
C
The field consists of radial lines originating from the wire
D
The field consists of concentric circles centred on the wire
Question 7
The direction of magnetic field around a straight conductor carrying current can be determined by ________
A
Fleming’s right hand rule
B
Fleming’s left hand rule
C
Lenz’s law
D
None of the above
Question 8
Magnetic field is produced by the flow of current in a straight wire. This phenomenon was discovered by ________
A
Maxwell
B
Faraday
C
Oersted
D
Coulomb
Question 9
The magnetic lines  of force, inside a current carrying circular loop are_______
A
circular at the ends but they are parallel to the axis inside the loop
B
along the axis are parallel to each other
C
perpendicular to the axis and equidistance from each other
D
concentric circles
Question 10
What is the direction of magnetic field at the centre of a coil carrying current in anticlockwise direction?
A
along the axis of the coil inwards
B
along the axis of the coil emerges outwards
C
perpendicular to the axis of the coil inwards
D
perpendicular to the axis of the coil outwards
Question 11
The strength of the magnetic field due to a current carrying conductor depends on _________
A
number of turns of a coil
B
magnitude of current
C
size of the coil
D
all the above
Question 12
The magnetic field produced due to a circular wire at its centre is _____
A
in the plane of the wire
B
perpendicular to the plane of the wire
C
at 450 to the plane of the wire
D
none of the above
Question 13
A current carrying conductor placed in a magnetic field experiences_______
A
mechanical force
B
magnetic force
C
electrical force
D
gravitational force
Question 14
A current carrying conductor experiences a force in a magnetic field was shown by _________
A
Hans Christian Oersted
B
Michael Faraday
C
Andre Marie Ampere
D
Fleming
Question 15
Name the effect of current when a current carrying conductor is placed in a magnetic field______
A
electrical effect
B
mechanical effect
C
magnetic effect
D
heating effect
Question 16
The direction of mechanical force produced by a current carrying conductor in a magnetic field is __________
A
perpendicular to the direction of magnetic field only
B
perpendicular to the direction of current flow
C
perpendicular to both the direction of current and magnetic field
D
parallel to the direction of magnetic field
Question 17
The direction of force on the current carrying conductor depends upon______
A
direction of current
B
direction of magnetic field
C
direction of suspension of a conductor
D
direction of current and direction of magnetic field
Question 18
The magnitude of mechanical force acting on a current carrying conductor in proportional to _________
A
current
B
magnetic induction
C
length of the conductor
D
all the above
Question 19
The force of a conductor is maximum when the current carrying conductor is _______
A
along the magnetic field
B
at right angles to the magnetic field
C
towards east
D
towards west
Question 20
When the current carrying conductor is placed along the direction of magnetic field, then the force is ________
A
maximum
B
minimum
C
zero
D
equal to one
Question 21
When a current carrying conductor is placed in a strong magnetic field, the direction of force is determined by __________
A
Right hand thumb rule
B
Fleming’s left hand rule
C
Fleming’s right hand rule
D
Faraday’s law
Question 22
In Fleming’s left hand rule, the first three fingers of the left hand are stretched at _______
A
acute angles
B
obtuse angles
C
right angles
D
none
Question 23
The motion of the conductor in Fleming’s left hand rule is represented by ________
A
fore finger
B
thumb
C
middle finger
D
none
Question 24
In Fleming’s left hand rule, the forefinger represents the direction of_________
A
magnetic field
B
current
C
motion of a conductor
D
electric field
Question 25
The direction of current in Fleming’s left hand rule is represented by ______
A
thumb
B
forefinger
C
middle finger
D
little finger
Question 26
An electric motor converts________
A
mechanical energy into electrical energy
B
mechanical energy into heat energy
C
electrical energy into heat energy
D
electrical energy into mechanical energy
Question 27
The coil used in a DC motor is called ______
A
split ring
B
armature
C
resistance coil
D
induction coil
Question 28
In DC motor, the split rings are known as ________
A
slip rings
B
armature
C
commutator
D
resistor
Question 29
An electric motor uses __________ to reverse current.
A
transformer
B
sliprings
C
commutator
D
brushes
Question 30
The direction of force in DC motor is given by __________
A
Fleming’s left hand rule
B
Fleming’s right hand rule
C
Right hand thumb rule
D
Lenz law
Question 31
In DC motor, the two equal and opposite forces constitutes________
A
torque
B
magnetic induction
C
couple
D
restoring
Question 32
. In DC motor, the couple rotates the coil in the _______
A
clockwise direction
B
upward direction
C
anticlockwise direction
D
downward direction
Question 33
The coil in electric motor continues to rotate in the anticlockwise direction as long as____
A
existence of magnetic field
B
current in the coil is zero
C
at restoring force in the coil
D
current flows through it
Question 34
The couple in an electric motor is to ____
A
vibrate the coil
B
stop the coil
C
rotate the coil
D
oscillate the coil
Question 35
The power of an electric motor can be increased by ______
A
increasing the number of turns in armature
B
decreasing the number of turns in the coil
C
decreasing the current
D
decreasing the strength of the magnetic field
Question 36
In an electric motor when the current is increased, ________
A
energy is increased
B
power is decreased
C
power is increased
D
energy is decreased
Question 37
The total number of magnetic lines of forces crossing a given area is _______
A
magnetic field
B
magnetic induction
C
magnetic strength
D
magnetic flux
Question 38
The commercial motors use______
A
electro magnet
B
permanent magnet
C
horse shoe magnet
D
bar magnet
Question 39
The phenomenon of electromagnetic induction was discovered by _______
A
Ampere
B
Christian Oersted
C
Lenz
D
Michael Faraday
Question 40
Electromagnetic induction is involved in _______
A
rotation of the coil of an electric motor
B
charging a body with negative
C
production of current by relative motion between a magnetic and a coil
D
generation of magnetic field due to a current carrying loops
Question 41
The generation of emf by varying the magnetic field is ______
A
electrostatic induction
B
magnetic induction
C
electromagnetic induction
D
mechanical effect of current
Question 42
In Faraday’s experiments, there is a deflection in the galvanometer when a ______
A
magnet is moved towards the coil
B
coil is moved towards the magnet
C
by changing the magnitude of current
D
all the above
Question 43
The current due to the relative motion between the coil and the magnet is called_________
A
direct current
B
alternating current
C
induced current
D
none of these
Question 44
The phenomenon of inducing an emf, when the magnetic flux linked with a coil, changes is called______
A
electromagnetic induction
B
electric induction
C
electrostatic induction
D
magnetic induction
Question 45
The induced emf depends on ______
A
magnetic induction
B
number of turns of the coil
C
relative speed between the magnet and the coil
D
all the above
Question 46
The induced emf is independent on __________
A
magnetic induction
B
number of turns of the coil
C
relative speed between the magnet and the coil
D
length of the magnet
Question 47
Who stated that whenever there is a change in the magnetic flux linked with a coil an emf is induced in it?
A
Faraday’s law
B
Newton’s law
C
Fleming’s left hand rule
D
generator rule
Question 48
The direction of induced current is given by ______
A
Ampere rule
B
Fleming’s left hand rule
C
Fleming’s right hand rule
D
Thumb rule
Question 49
When a current carrying conductor is placed in a strong magnetic field, the direction of force is determined by ________
A
Fleming’s left hand rule
B
Faraday’s law
C
Fleming’s right hand rule
D
Right hand thumb rule
Question 50
Fleming’s right hand rule is also known as ___________
A
motor rule
B
cork screw rule
C
thumb rule
D
generator rule
Question 51
In Fleming’s right hand rule, the thumb represents________
A
direction of magnetic field
B
direction of induced current
C
direction of force
D
motion of conductor
Question 52
The middle finger in the Fleming’s right hand rule represents _________
A
direction of induced current
B
direction of magnetic field
C
direction of force
D
motion of conductor
Question 53
Which phenomenon is used to produce large currents?
A
Magnetic induction
B
Electrostatic induction
C
Electromagnetic induction
D
Friction
Question 54
Generator is used to convert______
A
mechanical into electrical energy
B
electrical into mechanical energy
C
electrical into sound energy
D
sound into electrical energy
Question 55
AC generator works on the principle of ________
A
photo electric effect
B
mechanical effect of current
C
electrostatic induction
D
electromagnetic induction
Question 56
In an Ac generator, the direction of the induced emf at any instant is given by ______
A
Fleming’s right hand rule
B
Fleming’s left hand rule
C
Cork screw rule
D
Right hand thumb rule
Question 57
The field magnet used in AC generator is ______
A
an electromagnet
B
horse shoe magnet
C
bar magnet
D
powerful permanent magnet
Question 58
In generator, the armature is rotated about its axis______
A
parallel to the magnetic field
B
parallel to the direction of induced emf
C
perpendicular to the direction of magnetic field
D
perpendicular to the direction of induced emf
Question 59
The two ends of the coil in AC generator is connected to ________
A
brushes
B
slip rings
C
split rings
D
axle
Question 60
When the coil is rotated about an axis perpendicular to the direction of magnetic field in AC generator, there is a continuous change in the ________
A
induced current
B
induced emf
C
magnetic pole strength
D
magnetic flux
Question 61
In generator, the change in the magnetic flux linked with the coil induces_______
A
charges
B
current
C
an emf
D
electric field
Question 62
The direction of induced current at any instant in generator is given by _______
A
cork screw rule
B
ampere’s rule
C
Fleming’s right hand rule
D
Fleming’s left hand rule
Question 63
In AC generator, the emf varies for every_______
A
full rotation of the coil
B
half rotation of the coil
C
one fourth rotation of the coil
D
three fourth rotation of the coil
Question 64
A current which changes direction after equal intervals of time is _____
A
direct current
B
eddy current
C
alternating current
D
steady current
Question 65
The principle used in DC generator is ________
A
mechanical effect of current
B
electromagnetic induction
C
electrostatic induction
D
Ampere’s law
Question 66
DC generator is used to generate ______
A
steady current
B
eddy current
C
unidirectional current
D
alternating current
Question 67
The ends of the coil in DC generator is connected to ________
A
split rings
B
slip rings
C
brushes
D
axle
Question 68
The rectangular coil of many turns wound on a soft iron core is called _______
A
split rings
B
carbon brushes
C
armature
D
slip rings
Question 69
The split rings in a DC generator is used to ______
A
increase the current
B
decrease the current
C
reverse the current
D
invert the current
Question 70
Which part is used to convert AC into DC?
A
slip rings
B
carbon brushes
C
coil
D
split rings
Question 71
. The induced current from the generator is passed to the external circuit through ________
A
split rings
B
armature
C
commutator
D
carbon brushes
Question 72
In an AC generator, the emf obtained can be increased by ________
A
increasing the numbers of turns of the coil
B
increase the speed of rotation of the coil
C
using a strong field magnet
D
all the above
Question 73
Alternating current changes its direction ________
A
uniformly
B
periodically
C
instantaneously
D
spontaneous
Question 74
Mirrors having a spherical surface of reflection are ______
A
plane mirrors
B
lenses
C
spherical mirrors
D
prism
Question 75
A spherical mirror, which has reflecting curved inward surface is _________
A
concave mirror
B
convex
C
Plano concave
D
Plano convex
Question 76
The mirror that diverges the light rays is ________
A
concave
B
convex
C
plane
D
none
Question 77
The centre of the sphere, of which a spherical mirror is a part is called ________
A
pole
B
radius of curvature
C
focus
D
centre of curvature
Question 78
The centre of the reflecting surface of a spherical mirror is ________
A
centre of curvature
B
focus
C
pole
D
radius of curvature
Question 79
The point at which the rays are converged or diverged by a mirror is ______  
A
pole
B
principal focus
C
principal axis
D
centre of curvature
Question 80
The radius of curvature of the spherical mirror is equal to ______
A
focal length
B
twice the focal length
C
thrice the focal length
D
half of the focal length
Question 81
Which mirror is called converging mirror?
A
plane
B
convex
C
concave
D
plane concave
Question 82
A virtual and equal sized image is formed by _______
A
concave mirror
B
convex mirror
C
plane mirror
D
none
Question 83
To form a real image, the mirror required is ______
A
concave
B
convex
C
plane
D
none
Question 84
A virtual and enlarged image is formed by ________
A
convex mirror
B
concave mirror
C
plane mirror
D
both concave and convex mirror
Question 85
  1. A real image is always inverted
  2. A virtual image is always erect
A
only I is true
B
only II is true
C
both I and II are true
D
neither is true
Question 86
To form a virtual image, we use_____
A
only convex mirror
B
only concave mirror
C
either convex or concave mirror
D
plane mirror
Question 87
According to ________ of light, angle of incidence is equal to angle of reflection.
A
refraction
B
dispersion
C
reflection
D
total internal reflection
Question 88
A coin at the bottom of a bucket filled with water is appeared to be raised due to _____
A
dispersion
B
reflection
C
diffraction
D
refraction
Question 89
To obtain magnified, erect image in a concave mirror, object should be held______
A
at pole (P)
B
at focus(F)
C
beyond 2F
D
between O and (F)
Question 90
An object is placed at focus of a concave mirror, image is formed at ________
A
infinity
B
behind the mirror
C
focus
D
centre of curvature
Question 91
The image formed by a concave mirror is real, inverted and of same size as that of the object. The position of the object is _________
A
at F
B
at C
C
between F and 2F
D
beyond 2F
Question 92
An object is placed between F and 2F of a concave mirror, image will be formed ________
A
at infinity
B
beyond F
C
beyond 2F
D
between F and O
Question 93
To obtain same, real and inverted image in concave mirror object should be placed _______
A
at F
B
at 2F
C
beyond 2F
D
between F and optical centre
Question 94
When an object is placed between F and optical centre O in concave mirror the image formed will be _______
A
real-inverted and diminished
B
virtual- inverted and diminished
C
virtual-erect and diminished
D
virtual-erect and enlarged
Question 95
The mirror is used _________
A
to get powerful parallel beam of light
B
to obtain a magnified images
C
to produce heat
D
all the above
Question 96
Concave mirror is used_______
A
to get powerful parallel beam of light
B
to obtain magnified images
C
to produce heat
D
all the above
Question 97
Which mirror is used in solar furnaces?
A
concave
B
convex
C
plane
D
none
Question 98
The image formed by a spherical is virtual, erect and smaller in size, whatever be the position of the object, the mirror is _____
A
concave
B
convex
C
plane
D
both convex and concave
Question 99
When an object is placed at the principal focus of the convex lens the image formed is ______
A
enlarged
B
diminished
C
highly enlarged
D
highly diminished
Question 100
In automobiles, the mirror used to see the rear view is ________
A
concave
B
plane
C
convex
D
parabolic mirror
Question 101
Convex mirrors are preferred because_________
A
it gives powerful parallel beams
B
it concentrates the light
C
always give an erect image
D
it gives real inverted image
Question 102
Which mirror is used by ENT specialists and dentists?
A
concave mirror
B
plane
C
convex
D
parabolic
Question 103
Which mirror is used as shaving mirror?
A
concave
B
plane
C
convex
D
parabolic
Question 104
The mirror used by a dental surgeon is ______
A
concave
B
plane
C
convex
D
both concave and convex
Question 105
All the distances measured to the right of the origin is taken as ______
A
positive
B
negative
C
either positive or negative
D
none
Question 106
The distance of the image is from the pole of the mirror is called ______ a
A
focal length
B
image distance
C
object distance
D
principal axis
Question 107
The distance of the principal focus from the pole is called _______
A
focal length
B
image distance
C
object distance
D
principal axis
Question 108
Object distance is the distance between ______
A
pole and the image
B
pole and the object
C
principal focus and the pole
D
none of the above
Question 109
. For a concave mirror, value of v is positive, if image formed is _______
A
virtual
B
real
C
diminished
D
magnified
Question 110
Which mirror has a negative focal length?
A
Plane
B
Concave
C
Convex
D
All the above
Question 111
Which mirror has a negative value of v and forms a real image?
A
Plane
B
Concave
C
Convex
D
None
Question 112
For a convex mirror, the image distance is always ________
A
positive
B
negative
C
small
D
large
Question 113
The distance of the image of an object in spherical mirror is measured from the______  
A
focus
B
centre of curvature
C
pole
D
infinity
Question 114
Which of the following represent the unit of magnification?
A
dioptere
B
metre
C
decimetre
D
no unit
Question 115
Refraction takes place through _________
A
opaque
B
transparent
C
metals
D
none
Question 116
Magnification of a concave mirror is ________
A
less than one
B
more than one
C
more or less than one
D
infinity
Question 117
A convex mirror has a magnification which is always ________
A
equal to one
B
less than one
C
more than one
D
infinity
Question 118
When a ray of light travels from water to glass, it bends______
A
towards normal
B
away from normal
C
neither towards nor away from normal
D
along the normal
Question 119
Light travels fastest in ________
A
vacuum
B
air
C
glass
D
diamond
Question 120
No refraction occurs when a ray goes from _______
A
rarer to denser medium
B
denser to rarer medium
C
one medium to other medium of same optical density
D
none
Question 121
The angle between the normal and the refracted ray is called______
A
angle of reflection
B
angle of refraction
C
angle of incidence
D
angle of deviation
Question 122
The second law of refraction is stated by ________
A
C.V.Raman
B
Newton
C
Snell
D
Gallile
Question 123
Value of refractive index does not depend on ________
A
angle of incidence
B
substance of medium
C
temperature
D
speed of light in medium
Question 124
An imaginary straight line passing through the two centres of curvature of a lens is _____
A
focal length
B
radius of curvature
C
aperture
D
principal axis
Question 125
The effective diameter of length of a lens from whose refraction takes place is called _______
A
focus
B
centre of curvature
C
aperture
D
optic centre
Question 126
. In case of thin lenses, radius of curvature is _________
A
greater than aperture
B
lesser than aperture
C
equal to aperture
D
very much lesser than aperture
Question 127
The central point of a lens is called ________
A
centre of curvature
B
optical centre
C
principal focus
D
aperture
Question 128
Optic centre is ________
A
necessarily at the centre of lens
B
necessarily inside the lens
C
necessarily on principal axis
D
can be anywhere
Question 129
The light rays passing through the optic centre will_______
A
converge
B
diverge
C
reflect
D
emerge undeviated
Question 130
A ray passing through the focus of the less will ______
A
converge
B
diverge
C
emerges parallel to the principal axis
D
none
Question 131
An object is placed away from 2F of a convex lens, image is formed ______
A
at F
B
between F and 2F
C
at F
D
at infinity
Question 132
Virtual, erect and enlarged image is produced by convex lens when the object is placed ______
A
beyond 2F
B
between F and 2F
C
at F
D
between F and optic centre(O)
Question 133
If the object at 2F in case of a convex lens, image is necessarily at _________
A
F
B
2F
C
infinity
D
O
Question 134
The image formed by a convex lens, when the object is placed between F and 2F is ______
A
real-inverted and diminished
B
real-inverted and of same size
C
real- inverted and enlarged
D
virtual- erect and enlarged
Question 135
A convex lens does not produce _______
A
virtual diminished image
B
virtual enlarged image
C
real magnified image
D
real diminished image
Question 136
For a convex lens, as the object distance(u) increases, the image distance(v)________
A
remains constant
B
increases
C
decreases
D
is infinity
Question 137
Which lens is used as a magnifying glass?
A
convex
B
concave
C
biconcave
D
Plano concave
Question 138
A concave lens is a_____
A
diverging lens
B
converging lens
C
magnifying lens
D
plane lens
Question 139
The image formed by concave lens is always_______
A
real-inverted and diminished
B
real-inverted and of same size
C
real- erect and enlarged
D
virtual-erect and diminished
Question 140
Which statement is correct about a concave lens__________
A
object distance (u) is negative
B
focal length is negative
C
image distance(v) is negative
D
all the above
Question 141
The reciprocal of focal length of a lens is _______
A
principal focus
B
power
C
magnification
D
image distance
Question 142
The SI unit of power of lens is ______
A
metre
B
decimetre
C
dioptre
D
no unit
Question 143
The focal length of lens is 1 metre, then its power is _________
A
1 dioptre
B
1 metre
C
1 decimetre
D
1
Question 144
Image of real object formed by concave lens is ________
A
always real
B
always virtual
C
sometimes real
D
sometimes virtual
Question 145
Various colours in a rainbow is due to _________
A
reflection
B
refraction
C
deviation
D
dispersion
Question 146
A prism is a transparent medium bounded by two ______
A
non-parallel plane surfaces
B
parallel plane surfaces
C
spherical surfaces
D
concave surfaces
Question 147
Dispersion takes place due to ________
A
different speed of different colours of light
B
all colours of light travel with same speed
C
reflection by the prism
D
transparent medium
Question 148
Spectrum is the band of distinct _________
A
7 colours
B
9 colours
C
5 colours
D
8 colours
Question 149
Twinkling of stars is due to ______
A
reflection
B
dispersion
C
atmospheric refraction
D
none of the above
Question 150
White light is made up of _______
A
seven colours
B
six colours
C
all colours
D
no colour
Question 151
Light enters the eye through _______
A
pupil
B
iris
C
cornea
D
retina
Question 152
In a human eye, the image is formed at ________
A
pupil
B
iris
C
cornea
D
retina
Question 153
The amount of light entering the eye is adjusted by ________
A
pupil
B
iris
C
cornea
D
retina
Question 154
The size of pupil of the eye is adjusted by ______
A
cornea
B
iris
C
retina
D
ciliary muscles
Question 155
Eye lens is a _______
A
double convex lens
B
double concave
C
Plano convex lens
D
Plano concave lens
Question 156
The eye lens forms an image on the retina is_______
A
inverted – real image
B
erect- real image
C
virtual erect image
D
virtual-inverted image
Question 157
A person can see an object, when its image is formed ______
A
in front of retina
B
in front of cornea
C
away from retina
D
on the retina
Question 158
. The least distance of distinct vision is  _______
A
25 cm
B
35cm
C
20 cm
D
infinity
Question 159
. Focal length of eye lens increases permanently or contraction of the eye ball results in __________
A
myopia
B
presbyopia
C
hypermetropia
D
astigmatism
Question 160
A convex lens is used to rectify ___
A
myopia
B
presbyopia
C
hypermetropia
D
astigmatism
Question 161
Ageing results in _______
A
myopia
B
presbyopia
C
hypermetropia
D
astigmatism
Question 162
Elongation of the eye ball results________
A
myopia
B
presbyopia
C
hypermetropia
D
astigmatism
Question 163
Which lens is used to rectify myopia?
A
convex
B
concave
C
bifocal
D
cylindrical
Question 164
Myopia is also known as_______
A
near sightedness
B
far sightedness
C
refractive defects
D
none
Question 165
An old person cannot see nearby and distant objects can use ____
A
convex
B
concave
C
cylindrical
D
bifocal
Question 166
. Presbypia arises due to ____
A
contraction of eye ball
B
elongation of eye ball
C
diminishing flexibility of eye ball
D
none of the above
Question 167
The person cannot donate eyes, who is suffering from ________
A
asthma
B
diabetes
C
hypertension
D
leukaemia
Question 168
Focal length of the eye lens is ________
A
fixed
B
variable
C
either fixed or variable
D
neither fixed nor variable
Question 169
Variable focal length of eye lens is responsible for _______
A
accommodation of eye
B
colour blindness
C
persistence of vision
D
least distance of distinct vision
Question 170
When we go out in the bright sunlight, the pupil of the eye_______
A
contracts
B
expands
C
sometimes expands
D
neither contracts nor expands
Question 171
Which telescope was carried by a space shuttle?
A
astronomical
B
Hubble
C
terrestrial
D
none
Question 172
Hubble’s telescope is used _______
A
to measure the expansion of universe
B
to find block holes
C
to observe distant supernova
D
all the above
Question 173
The radius of curvature of a concave mirror is -10 cm. its focal length is ___
A
20 cm
B
-5 cm
C
5 cm
D
10 cm
Question 174
Concave mirror produces 10 cm long image of an object of height 2 cm. The magnification is ________
A
5
B
20
C
10
D
2
Question 175
Which of the following controls the pupil of the human eye?
A
cornea
B
citrary muscles
C
Iris
D
Retina
Question 176
A device which converts electrical energy into mechanical energy is _______
A
Generator
B
Motor
C
Transformer
D
Power supply
Question 177
The defect myopia can be corrected by using a _______
A
convex lens
B
concave lens
C
concave mirror
D
convex mirror
Question 178
The defect hypermetropia can be corrected by using a _______
A
convex lens
B
concave lens
C
concave mirror
D
convex mirror
Question 179
The amount of induced e.m.f when the magnetic field linked with the coil changes is ______
A
magnetic induction
B
current produced
C
e.m.f produced
D
changing current
Question 180
______ discovered electromagnetic induction.
A
Oersted
B
Faraday
C
Edison
D
Newton
Question 181
The type of mirror used in Hubble space telescope is _______
A
Hyperbolic mirror
B
Concave mirror
C
Convex mirror
D
Plane mirror
Question 182
Match the following
  1. Convex mirror                                                          a. Concave lens
  2. Radius of curvature of a spherical mirror             b. Metre
  3. Focal length                                                                c. Reflecting surface is curved outward
  4. Myopia                                                                              d. 2 x focal length
A
1 4 2 3
B
2 1 3 4
C
4 3 1 2
D
3 2 1 4
Question 183
Match the following
  1. Beyond 2F             a. Infinitely large
  2. At 2F                                   b. Enlarged
  3. At principal focus F           c. Same size
  4. Between F and 2F             d. Diminished
A
4 3 1 2
B
2 1 3 4
C
4 3 2 1
D
3 2 1 4
Question 184
Match the following
  1. Reciprocal of focal length     a. Metre
  2. Search light and vehicles     b. Telescope
  3. Focal length                         c. Power of a lens
  4. Supernovae                         d. Convex lens
A
3 4 1 2
B
2 1 3 4
C
4 3 2 1
D
4 3 1 2
Question 185
Match the following
  1. Iris                        a. Sending signal to the brain
  2. Optic nerves           b. A delicate membrane
  3. Retina                   c. Controls the amount of light entering
  4. Pupil                        d. A dark muscular diaphragm
A
3 4 1 2
B
2 3 4 1
C
2 1 3 4
D
4 3 1 2
Question 186
Match the following
  1. Concave mirror    a. Dispersion
  2. Refraction             b. Virtual and erect image
  3. Concave lens               c. Snell’s law
  4. Prism                           d. To produce heat in solar furnace
A
4 3 1 2
B
2 3 4 1
C
2 1 3 4
D
4 3 2 1
Question 187
Match the following
  1. Electric motor               a. Converts mechanical energy into electrical energy
  2. Electric generator              b. Generate electrical signal when illuminated
  3. Height sensitive cells             c. Black holes
  4. Hubble’s observations                   d. Converts electrical energy into mechanical energy
A
4 3 1 2
B
2 3 4 1
C
2 1 3 4
D
4 3 2 1
Question 188
A
A
B
B
C
C
D
D
Question 189
A
A
B
B
C
C
D
D
Question 190
A
A
B
B
C
C
D
D
Question 191
A
A
B
B
C
C
D
D
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There are 191 questions to complete.

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