Question # 1

Which Statemtn below correctly identifies the differecne between laws and theories.

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Laws describe phenomena , while theories explain why phenomena exist

Laws are a statment of fct, while theories are statemetn of opinion

Laws explain why phenomena exist, while theories explain how

Laws are a prediction of phenomena, while theories are an explanation.

A force is acting on body but causes no displacemtn. The work done on the body is

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Negative

Zero

Positive

Infinite

The rate of change of momentum of free falling body is equal to its.

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Size

Velocity

Weight

Momentum

Change in positionof a body from initial to final point is called

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Velocity

Speed

Displacement

Distance

A ball is thrown downward with an initial velocity, its.

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Ek increases and Ep decreases

Ek decreases and Ep increases

Both Ek and Ep increases

Both Ek and Ep decreases

Pressure of 1000 bars is equivalent is.

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0.1 kPa

100 k Pa

10 k Pa

1 k Pa

In 5 s a car accelerates so that its velocity increases by 20 m/s. The acceleration is

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0.25 m/s2

4 m/s2

100 m/s2

25 m/s2

A book of mass 5 kg is placed on the table, the magnitude of net force acting on the book is.

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0 N

25 N

5 N

10 N

Why do scientists develop a hypothesis before conducting research.

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Hypotheses help a researcher decide which observations to record and which to ignore

It give them direction on how to interpret the results of their research

It helps to predict outcomes and define the parameters of the rsearch

Hypotheses give the researcherr an outcome to shape their work around

The numerical ratio of displacemnt o distance is

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Equal to or less than one

Always greater than one

Always equal to one

Always less than one

If a bar magnet is cut in half it will become

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A monopole

Magnetized

Magnet of less strength

The same magnet

What happen to the atomic number of an element which emits one alpha particle?

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Increase by 1

Stays the same

Decrease by 2

Decrease by 1

Radiation was found in:

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1896

1895

1897

1898

Power of hair dryer is:

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1000 W

750 W

10 W

75 W

The half of carbon 14 is

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5720 years

5730 years

5740 years

5750 years

In a convex mirror the size of the image:

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Is smaller than the size of the object

Is greater than the size of the object

Depends upon the position of the object

Is equal to the size of the object

with the increase in temperature the resistance of pure metals:

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increases

decreases

remains same

none of these

Which device has two coils, primary and secondary?

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D.C. Motor

Transformer

A.C. genrator

a and b

When a potential of 10 volt is applied across a conductor, a current of 5 miliampere flows through it, the resistance of the conductor will be:

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200 ohm

2000 ohm

0.2 ohm

0.002 ohm

How does sound travel from its source to your ear?

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Byc changes in air pressure

By vibration in wires or strings

By electromagnetic waves

By infrared waves

Application of electrostatic is:

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Car painting

Photocopying

Extracting of dust

All of these

Battery converts chemical energy into which energy:

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Mechanical

Electrical

Thermal

None of these

Apparent weight of a man is in upward accelerated lift will

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Increases

Decreases

Remain same

Increases then decrees

The SI unit for measuring plane angle is

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Streadian

Radian

Both a and B

None of these

At which place the motion of a simple pendulum will be slowest.

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Karachi

K-2

Murree

Lahore

Which is unimportant in describing the satellites orbit.

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Distance of satellite from earth's center

Gravitational constant G

Mass of satellite

Mass of earth

If a body is moving in the counter clockwise direction the direction of angular velocity will be

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Toward the centre

Away from the centre

along the linear velocity

Perpendicular to both radius and linear velocity

The resultant of two vectors having magnitude 10 N and 8 N Can not be

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2 N

9 N

18 N

20 N

The ideal gas law is.

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PV =NVk

P = NkT

PV =nRT

P=nRT

When the rocket moves away from the earth, the work against gravity

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Remains constant

Varies directly with distance

Varies inversely with distance

Varies inversely with square of distance

Work has dimension lime

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Torque

Momentum

Velocity

Power

When a body is whirled in a horizontal circle by means of string, the centripetal force is supplied by

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Mass of body

Velocity of a body

Tension in the string

Centripetal acceleration

The wavelength of wave produced by microwave oven is.

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12 cm

12 m

18 m

18 cm

A device used for detection of current is called.

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Inductor

Voltmeter

Capacitor

Galvanometer

During electrolysis process, density of CuSO₄ solution

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Remains constant

Decreased

Increased

None of these

Tolerance of "Gold" band.

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±10%

±5%

±15%

±20%

A simple device that prevents the direction of current from changing is called.

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Commutator

Rotor

Armature

Detector

Drum of photocopier is made of.

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Copper

Aluminum

Nickel

Cobalt

100 micro F capacitor is connects to an AC voltage 24 V and frequency 50 Hz. The reactance of the capacitor is.

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30.8 Ohm

31.8 Ohm

34.8 Ohm

40 Ohm

A changing electric flux creates.

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Electric fields

Gravitational

Magnetic field

Electric charge

A pentaralent impurity in Si

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a free electron and a free hole

a free hole

a free electron

No free particle

Minority carriers in P-Types , substances are.

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Electrons

Protons

Holes

Neutrons

For automatic Switching of streetlight, the op amplifier is used as.

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Inductor

Converter

Comparator

Thermistor

Paschen series lies in the

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Far ultraviolet region

Visible region

Ultraviolet region

Inferred region