Download GROUND ZERO DEFENCE INSTITUTE PHYSICS 1. Which of

GROUND ZERO DEFENCE INSTITUTE
PHYSICS
1. Which of following is connected to
galvanometer when it is converted into an
ammeter?
a) low resistance in series
b) high resistance in series
c) low resistance in parallel
d) high resistance in parallel
2. With one unit of electricity a 100 W bulb can
burn for
a) 1 hr
b) 5 hrs c) 10 hrs d) 20 hrs
3. In electric supply lines in India, which parameter
is kept constant?
a) voltage
b) current
c) frequency
d) power
4. Transformer is a kind of appliance that can
1) increase power 2) increase voltage
3) decrease voltage 4) measure current and
voltage
a) 1,4
b) 4
c) 2,3
d) 2,3,4
5. A freely suspended magnetic needle at the
magnetic north pole of the earth
a) remains horizontal
b) remains vertical
c) makes an angle of 23 with vertical
d) makes an angle of 67 with vertical
6.. Consider the following
1. an ammeter should have low resistance .
2. an ammeter should have high resistance
3. a voltmeter should have low resistance.
4. a voltmeter should have high resistance.
a) 1,4
b) 1,3
c) 2,3
d) 2,4
7. The image formed on the retina of a human eye
a) virtual & inverted b) virtual & erect
c) real & erect
d) real & inverted
8. Consider the following statements :
1. The magnetic pole in the northern hemisphere
is the north magnetic pole.
2. At all points on a magnet an iron bar gets
attracted.
Which one of the statements given above is/ are
correct.
a) 1 only b) 2 only c) both d) neither
9. When an electric bulb breaks, what is the
reason for a mild bang?
a) a chemical reaction between the enclosed
gases
b) compared gases rush out suddenly
c) the air rushes in to fill the evacuated space
d) none.
10. A bullet travelling horizontally hits a block kept
at rest on a horizontal surface and gets embedded
into it, the two together then move with a uniform
velocity. Which of the following conservation laws
holds?
a) conservation of angular momentum
b) conservation of K.E.
c) conservation of linear momentum
d) conservation of velocity
11. The lines of force of uniform magnetic field
a) must be convergent
b) must be divergent
c) must be parallel to each other
d) intersect
12. When an electric bulb breaks, what is the reason
for a mild bang?
a) a chemical reaction between the enclosed gases
b) compressed gases rush out suddenly
c) the air rushes in to fill the evacuated space
d) none
13. Consider the following statement. Work is not
done, when
1. a man is walking on a horizontal road with a load
on his head.
2. a man is climbing up a hill with a load on his head.
3. moon is revolving round the earth.
Which of them are correct?
a) 1,3
b) 1,2
c) 2
d) 1
14. A bullet travelling horizontally hits a block kept at
rest on a horizontal surface and gets embedded into
it, the two together then move with a uniform
velocity. Which of the following conservation laws
holds?
a) conservation of angular momentum
b) conservation of K.E.
c) conservation of linear momentum
d) conservation of velocity
15. A DC voltmeter is capable of measuring a
max. of 300 volts. If it is used to measure voltage
across a device operating at 220 volt AC supply,
reading of voltmeter will be
a) 300 V b) 220 V c) 110 V d) 0 V
16. When a particular current flows through a
resistance wire:
a) the heat produced will be more if the current is
from a DC source.
b) the heat produced will be more if the current is
from an AC source
c) no heat will be produced.
d) heat produced will be independent of the nature
of the source of the current.
17. When a coil of wire is rotated in a uniform
magnetic field
a) alternating emf of constant angular frequency is
generated
b) direct current of constant emf is generated
c) alternating emf of varying frequency is
generated
d) DC of varying emf is generated
18. Which of the following is not true about
semiconductors.
a) at low temperatures, pure semiconductor
behaves as an insulator
b) the mobility of holes in a semi is greater than
that of electrons
c) the mobility of electrons and holes in a
semiconductor decrease with increase in
temperature
d) conductivity of semiconductor increases with
increase in temperature
19. Consider the following
The core of transformer is laminated because it
1. prevents leakage of flux
2. gives more secondary voltage
3. reduces eddy currents
Which of them are correct?
a)1
b) 1,2
c) 2,3
d) 3
20. Match
A. Fow current in metal
1. Faraday
B. Force acting on moving 2. Lorentz
ENERGIZING ENDEAVOUR FOR EXCELLENCE
Charge
C. Magnetic field around
3. Ohm
Current carrying cond.
D. Electrolysis
4. Biot – Savart
A
B
C
D
a) 3
2
1
4
b) 3
2
4
1
c) 2
3
4
1
d) 2
3
1
4
21. Match
A. Watt 1. Electric charge
B. Tesla 2. Power
C. Coulomb
3. Luminous intensity
D.Candela
4. Magnetic field
A
B
C
D
a) 2
4
3
1
b) 4
2
3
1
c) 2
4
1
3
d) 4
2
1
3
22. Consider the a static point charge. If this
charge is –ve, then the electric lines of force are
a) concentric circles with charge at the centre
b) straight lines radiating away from the charge
c) straight lines converging towards the charge
d) parallel straight lines
23. Consider the following
Household electrical appliances are not usually
connected in series because
1. switching off an appliance would switch off the
rest
2. a fuse would blow as soon as one appliance is
used
3. power consumption would be very much greater
4. the appliances would get damaged due to high
current
Which of them are correct?
a) 1
b) 2,3
c) 3,4
d) 1,2 and4
24. A charged particle moves with velocity v in a
uniform magnetic field B. the magnetic force
experienced by the particle is
a) always 0
b) 0, if B & v are inclined at 45
c) 0, if B & v are perpendicular
d) 0, if B & v are parallel
25. Match
A. Gilbert
1. Force between 2 charges
B. Coulomb
2. Electromagnetic theory
C. Oersted
3. Properties of magnet
D. Maxwell
4. Magnetic effect of electric
current
A
B
C
D
a) 2
4
1
3
b) 3
4
1
2
c) 3
1
4
2
d) 2
1
4
3
26. 10 electric bulbs are connected in series
across a 220 V supply. After one bulb is fused the
remaining nine are connected again in series
across the same supply. Then the illumination will
be
a) more with 10 bulbs than that with 9 bulbs
b) more with 9 bulbs than that with 10 bulbs
c) equal in both cases
d) in the ration of 102 : 92
GROUND ZERO DEFENCE INSTITUTE
27. In a science laboratory a faulty Celsius
thermometer has divisions of equal size. It reads –
70 C when the actual temperature is 00 C and 880 C
when the actual temperature is 1000 C. what is the
actual temperature when this thermometer reads
500 C.
a)430 C b)570 C c)600 C d)620 C
28. Why does a lighting conductor have sharp
points
a) charge density & electric, field are relatively
high on sharp points
b) charge density and electric field are relatively
low on sharp points
c) charge density is low, but electric field is high
on sharp points
d) charge density is high, but electric field is low
on sharp points
29. Consider the following
1. water cannot be made to boil at 90 C.
2. charge on a conductor is mostly concentrated
at places where the surface is mostly plain
3. the resistance of a fuse wire is high.
Which of them are correct?
a) 1,2
b) 1
c) 3
d) all
30. The function of a safety fuse of a given
material is independent of which one of the
following
a) Radius of the fuse wire
b)Resistivity of the fuse wire
c)Length of the fuse wire
d)Current flowing through the fuse wire
31. Why does one experience a strong shock when
one accidentally touches a live wire of say, 220 v
a)the resistance of human body is very low
b)the resistance of human body is very high
c)the human body is sensitive to even feeble
currents
d)the human body is sensitive to large currents
only
32. Which one of the following statements is
correct
The space surrounding a charge in uniform
motion has
a)only an electric field
b) only a magnetic
field c) both electric and magnetic fields
d) neither an electric nor a magnetic field
33 Which of the following does not affect the
motion of a moving electron?
a) electric field applied in the direction of motion
b) magnetic field applied in the direction fo motion
c) electric field applied perpendicular to the
direction of motion
d) magnetic field applied perpendicular to the
direction of motion
34. Which of the following is the correct
statement?
A fairly uniform magnetic field is produced
a) inside a horse shoe magnet
b) inside a cylindrical conductor
c) inside a solenoid
d) between parallel conductors
35. Which of the following is correct?
Lightning is formed when
a) similar charges of electricity rush towards each
other & then get repelled
b) clouds strike against impurities in air and the
friction burns up these impurities
c) strong opposite charges in different clouds
break down the resistance offered by intervening
air.
d) water vapour produces electricity in the clouds.
36. The rating of an electric lamp is 110 V. To use
it on 220 V, one will have to use which one of the
following ?
a) Transistor
b) Resistor
c) Transformer
d) Generator
37. A wire has a resistance of 32 Ω. It is melted
and drawn into a wire of half of its original length.
What is the resistance of the new wire ?
a) 32Ω b)16Ω
c)8Ω
d)4Ω
38. Consider the following
Heat produced in a conductor carrying current is
independent of
1. current passing through it
2. thermal conductivity.
3. specific resistance
Which of them are correct.
a) 1,3
b) 2
c) 1,2
d) 2,3
39. DC current can be controlled by which of the
following
a) impedance b) resistance
c) capacitance
d) inductance
40. The electric charge is stored in a device called
a)inductor
b)capacitor
c)resistor
d)transformer
41. The force experienced by a unit positive test
charge placed at a point is called ?
a)magnetic field at that point b)gravitational field
at that point
c)electrical field at that point d)nuclear field at
that point
42. The effective resistance of 3 equal resistances,
each of resistance r, connected in parallel is
a) 3/r
b) r/3
c) 3r
d) r3
43.The magnetic lines of force due to the bar
magnet
a) intersect inside the body of the magnet
b) intersect at neutral points only
c) intersect only at north & south poles
d) cannot intersect at all
44.The specific resistance of a conducting wire
depends upon
a) length of the wire, area of cross section of the
wire & material of the wire
b) length of the wire & area of cross section of the
wire but not on the material of the wire
c) material of the wire only but neither on the
length of wire nor on the area of cross section of
the wire
d) length of wire only but neither on the area of
cross section of wire nor on the material of wire.
45. Magnetism of bar magnet can be destroyed if it
is
I. kept in magnetic meridian.
II. placed in a direction opposite to that of the
Earth’s horizontal intensity.
III. heated to a temperature known as Curie
temperature.
ENERGIZING ENDEAVOUR FOR EXCELLENCE
a) I, II
b) II
c) II, III d) I,II, III
46. Capacity of a parallel plate condenser can be
doubled by
I. doubling areas of the plates.
II. doubling distance of separation between the
plates.
III. reducing distance of separation between the
plates to half original separation.
IV. doubling both areas of the plates & the
distance of separation between plates.
a) I, IV
b) I, III
c) III
d) II, III
47. 2 pieces of metallic wire having equal lengths
& equal volume placed in air have different
resistances. The 2 wires must
a) have different cross sections
b) have different temperatures
c) be of different materials
d) be of same density
48. The direction of magnetic field at a point due
to an infinitely long wire carrying current is
a) parallel to current
b) antiparallel to the current
c) along the perpendicular drawn from a point on
the wire
d) perpendicular to the plane containing the
conductor and the point
49. A hollow metal ball carrying an electric charge
produces no electric field at points
a) outside the sphere
b) on its surface
c) inside the sphere d) only at the centre