PHYSICS TEST 8 - PAK ARMED FORCES TEST

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Results

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#1. The second law of thermodynamics is concerned with the situation in which

heat can be converted into work

direction of flow of heat

both A & B

none of these

#2. The percentage efficiency of Carnot’s engine

eta = (1 - T_1/T_2) x 100%

eta = (1 + T_2/T_1) x 100%

eta = (1 + T_1/T_2) x 100%

eta = (1 - T_2/T_1) x 100%

#3. The unit of thermodynamic temperature scale is

Celsius

Fahrenheit

kelvin

all of these

#4. Physics is one of the branches of

Life sciences

Physical sciences

Biological sciences

Social sciences

#5. The average speed of oxygen molecule in the air at S.T.P. is

459 ms^-1

460 ms^-1

461 ms^-1

462 ms^-1

#6. Which expression represents a NAND operation?

X = A*B + A*B

X = A*B + AB

X = A + B

X = A bullet B with bar over it

#7. A common point between OR and AND gates is that

their outputs may be 1 even when either of their inputs is at 2

their outputs are 5 when their all inputs are at 6

their outputs may be 1 even when either of their inputs is 3

none of these

#8. The production of electrons in a cathode-ray tube is

from a radioactive source

by ionization of the air

by applying an electric field to the X-plates

by heating the filament

#9. A sinusoidal trace is observed on a CRO screen. For this alternating potential was given to

The anode

The cathode

The filament

The Y-plates

#10. If a charge Q is dispersed over two spheres of radii R and r such that their surface charge densities are equal. What is the ratio of the charges on the spheres?

2r / R

R^2 / r^2

r^3 / 5R^3

r^4 / R^4

#11. There are three bulbs of 60W, 100W and 200 W which bulb has thickest filament.

100W

200W

60W

All

#12. Scalar product of a vector A with itself is

A^2

A/2

#13. Electrical energy is measured in

watt

horse power

kilo watt

kilowatt hour

#14. Electrical energy is converted to heat at the rate of

IRt

I^2R

I^2Rt

VIt

#15. Which one of the following bulbs has the least resistance?

100 watt

400 watt

500 watt

60 watt

#16. Which one of the following is scalar?

magnetic field

flux density

magnetic flux

induced emf

#17. Transformer works on

A.C only

D.C.

high voltage only

A.C. & D.C

#18. The neutral point in a magnetic field will be a point at which

The resultant magnetic intensity is zero

earth's field is zero

the magnetic field is zero

the magnetism is more

#19. At Curie temperature the ferromagnetic materials get converted into

non-magnetic material

paramagnetic material

diamagnetic material

all of the above

#20. A galvanometer gives full scale deflection when the current passing through it is 1mA. Its resistance is 100 Omega. Without connecting additional resistance in series with it, it can be used as a voltmeter of range.

0.010 V

00.100 V

0.100 V

#21. The needle of the dip circle at a place stays at 30°. The dip circle is inclined at an angle of 30° with the magnetic meridian. The true dip at the place is

tan^-1 sqrt{3}

tan^-1 (sqrt{3}/5)

tan^-1 (1/2)

tan^-1 (4/2)

#22. If in a photoelectric cell, the wavelength of incident light is changed from 4000 A to 3600 A, then the change in stopping potential will be

0.34 volt

0.57 volt

0.71 volt

0.23 volt

#23. A stopping potential of 0.82 volt is required to stop the photo electron emitted from a metallic surface by light wavelength 400A. The stopping potential for wavelength 3000A will be

Volt

1.85 volt

2.03 volt

2.5 volt

#24. A block of mass m and charge q is place on a smooth horizontal table which terminates in a vertical wall at a distance d from the block. A horizontal electric field E toward right is switched on. Assuming elastic collision, find time period of the resulting oscillatory motion.

sqrt{8dm / qE}

sqrt{4dm / qE}

sqrt{2dm / qE}

None of these

#25. The center of gravity of a cylinder is at

The center of the top of the cylinder

The center of the bottom of the cylinder

A point on curved side on of the cylinder

The mid-point of axis

#26. When an electron jumps from a higher to a lower orbit, the energy of the photon emitted depends upon

The energy of higher orbit only

The energy of lower orbit only

The energies of higher and lower orbits

The energy of any orbit.

#27. How can we increase the period of oscillation of a mass spring system?

By increasing mass attached to the spring

Keeping mass attached with the spring constant

Decreasing mass attached with the spring

By decreasing mass of the spring.

#28. Which one of the following is a vector quantity?

Current density

Angle

Electric current

Gravitational potential

#29. Threshold frequency is the frequency below which

Photo current is constant

Photo current increases with voltage

Photo current decreases with voltage

Photoelectric emission is not possible

#30. Lenz’s low provides a relation between

Current and magnetic field

Induced emf and the rate of change of magnetic flux

Force on a current carrying conductor and magnetic field

None of the above

#31. Which one of the following properties of waves is not found collectively in both sound waves and radio waves?

Interference

Diffraction

Polarization

Refraction

#32. For rectifying action we use

Choke

Transformer

Diode

Condenser

#33. Which one of the following is the dimensional formula for angular momentum?

ML^-2T^-1

ML^2T^-2

M^2L^0T^-2

ML^2T^-1

#34. Magnetic flux passing normally through a unit area is called

Flux density

Megnetic field intensity

Magnetic field lines

Magnetization

#35. Photo cell works

In the presence of light of frequency greater than threshold frequency

In the absence of light

In the presence of light of frequency less than threshold frequency

None of the above

#36. A heat engine working in between two isothermals and two adiabatic is called

Diesel engine

Claudius engine

Rankine engine

Carnot engine

#37. Resistance of a conductor increases as its

Length increases

Length decreases

Area increases

Resistivity decreases

#38. A satellite is orbiting round the earth in a circular orbit. It moves with

Constant speed

Constant angular acceleration

Constant acceleration

None of these

#39. In order to observe two successive bright or dark fringes in Michelson’s interferometer, the movable mirror is displaced through a distance of

lambda

lambda / 2

lambda / 4

2 lambda

#40. Which one of the following discarded the idea of either?

Schrodinger

DeBroglie

Michelson and Morley

-Henry

#41. A body of mass m is moving in a circle of radius r with a constant speed v. The force on the body is mv^2/r and is directed towards the center. What is the work done by this force in moving the body over half the circumference of the circle?

(mv^2 / r) * (pi r)

pi r^2 / mv^2

mv^2 / r^2

Zero

#42. The unit of torque in SI system is

N-m^2

N-m^3

N-m

N-m^-1

#43. If a simple pendulum is vibrating then (I) Length of pendulum and time period is directly proportional, (II) Time period of pendulum is independent of the mass of the bob, (III) Time period depends upon the value of the g.

I and II are correct

II and III are correct

I and III are correct

I, II and III are correct

#44. According to Bohr’s theory of hydrogen atom, the angular momentum of electron in allowed orbit is

nh / pi

nh / 2pi

n / 2pi h

2pi h / n

#45. A lift is failing freely after the breakdown of its suspension. The weight of person inside the lift would become

Zero

Half

Double

Four times

#46. Clock-wise torque is taken as

+ve

-ve

Neither +ve nor -ve

Zero

#47. The unit of Plank’s constant in C.G.S system of units is

Joules/sec

Joules*sec

Joules/sec^2

Sec/Joules

#48. A ball is thrown horizontally from the of 490 m high cliff with a velocity of 10 m/sec. It experiences (I) Horizontal acceleration equal to zero, (II) Vertical acceleration of 9.8 m/sec^2, (III) Angular acceleration of 9.8 rad/sec^2

I only is true

I and II only are true

II and III only are true

I, II and III are true

#49. A source of sound waves towards a stationary observer. The apparent frequency heard by the observer is

Greater than actual frequency

Less than actual frequency

Equal to actual frequency

None of the above

#50. Resistivity of a conductor is of the order of

10^-8 ohm-meter

10^4 ohm-meter

10^8 ohm-meter

10^10 ohm-meter

Finish

Results

#1. The second law of thermodynamics is concerned with the situation in which

#2. The percentage efficiency of Carnot’s engine

#3. The unit of thermodynamic temperature scale is

#4. Physics is one of the branches of

#5. The average speed of oxygen molecule in the air at S.T.P. is

#6. Which expression represents a NAND operation?

#7. A common point between OR and AND gates is that

#8. The production of electrons in a cathode-ray tube is

#9. A sinusoidal trace is observed on a CRO screen. For this alternating potential was given to

#10. If a charge Q is dispersed over two spheres of radii R and r such that their surface charge densities are equal. What is the ratio of the charges on the spheres?

#11. There are three bulbs of 60W, 100W and 200 W which bulb has thickest filament.

#12. Scalar product of a vector A with itself is

#13. Electrical energy is measured in

#14. Electrical energy is converted to heat at the rate of

#15. Which one of the following bulbs has the least resistance?

#16. Which one of the following is scalar?

#17. Transformer works on

#18. The neutral point in a magnetic field will be a point at which

#19. At Curie temperature the ferromagnetic materials get converted into

#20. A galvanometer gives full scale deflection when the current passing through it is 1mA. Its resistance is 100 Omega. Without connecting additional resistance in series with it, it can be used as a voltmeter of range.

#21. The needle of the dip circle at a place stays at 30°. The dip circle is inclined at an angle of 30° with the magnetic meridian. The true dip at the place is

#22. If in a photoelectric cell, the wavelength of incident light is changed from 4000 A to 3600 A, then the change in stopping potential will be

#23. A stopping potential of 0.82 volt is required to stop the photo electron emitted from a metallic surface by light wavelength 400A. The stopping potential for wavelength 3000A will be

#24. A block of mass m and charge q is place on a smooth horizontal table which terminates in a vertical wall at a distance d from the block. A horizontal electric field E toward right is switched on. Assuming elastic collision, find time period of the resulting oscillatory motion.

#25. The center of gravity of a cylinder is at

#26. When an electron jumps from a higher to a lower orbit, the energy of the photon emitted depends upon

#27. How can we increase the period of oscillation of a mass spring system?

#28. Which one of the following is a vector quantity?

#29. Threshold frequency is the frequency below which

#30. Lenz’s low provides a relation between

#31. Which one of the following properties of waves is not found collectively in both sound waves and radio waves?

#32. For rectifying action we use

#33. Which one of the following is the dimensional formula for angular momentum?

#34. Magnetic flux passing normally through a unit area is called

#35. Photo cell works

#36. A heat engine working in between two isothermals and two adiabatic is called

#37. Resistance of a conductor increases as its

#38. A satellite is orbiting round the earth in a circular orbit. It moves with

#39. In order to observe two successive bright or dark fringes in Michelson’s interferometer, the movable mirror is displaced through a distance of

#40. Which one of the following discarded the idea of either?

#41. A body of mass m is moving in a circle of radius r with a constant speed v. The force on the body is mv^2/r and is directed towards the center. What is the work done by this force in moving the body over half the circumference of the circle?

#42. The unit of torque in SI system is

#43. If a simple pendulum is vibrating then (I) Length of pendulum and time period is directly proportional, (II) Time period of pendulum is independent of the mass of the bob, (III) Time period depends upon the value of the g.

#44. According to Bohr’s theory of hydrogen atom, the angular momentum of electron in allowed orbit is

#45. A lift is failing freely after the breakdown of its suspension. The weight of person inside the lift would become

#46. Clock-wise torque is taken as

#47. The unit of Plank’s constant in C.G.S system of units is

#48. A ball is thrown horizontally from the of 490 m high cliff with a velocity of 10 m/sec. It experiences (I) Horizontal acceleration equal to zero, (II) Vertical acceleration of 9.8 m/sec^2, (III) Angular acceleration of 9.8 rad/sec^2

#49. A source of sound waves towards a stationary observer. The apparent frequency heard by the observer is

#50. Resistivity of a conductor is of the order of

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❌ Your Wrong Attempts: