Question # 1

If a car moves with a uniform speed of 2 ms-1 in a circle of radius 0.4m. Its angular speed is

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4 rad. s^-1

1.6 rad. s^-1

5 rad. s^-1

2.8 ms^-1

A total charge of 100C flows through 12W bulb in a time of 50 second. Which is the potential difference across the bulb during this time?

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0.12V

6.0V

2.0V

24V

Absolute zero is considered as that temperature at which:

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All liquids become gases

All gases become liquids

Water freezes

None of these

A charge is 90C passes through a wire in 1 hour and 15 minutes. Wat is the current in the wire?

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10mA

20mA

15mA

25mA

A body revolved around the sun 27 times faster then the earth what is the ratioof their radii

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1/27

1/4

1/9

1/3

The fundamental frequency of a closed organ pope is 50 Hz. The frequency ofsecond over tone is

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100hz

150hz

60hz

250hz

The dimensions of Planck’s constant “h” are same as that of:

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Momentum

Angular momentum

Work

Torque

A.H Compton studied the scattering of X-rays by loosely bound electrons from a graph target in:

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1905

1911

19251

1923

Area under Q-V graph for a capacitor represents

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Charged stored

Energy stored

Electric field strength

Potential difference

The relative permittivity of air is

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1

3.7

7.8

1.0006

SI unit of kinetic energy of rotation is

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joule second

joule

joule second

joule meter

Two bodies moving towards each other collide and move away in opposite directions. There is some rise in temperature of bodies because a part of the kinetic energy is converted into

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heat energy

electrical energy

nuclear energy

mechanical energy

If the range of a projectile is R, the potential energy will be maximum after the projectile has covered (from start) distance equal to:

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R/2

R/4

R

R/9

A diode characteristics curve is a graph plotted between;

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Current and time

Voltage and time

Voltage and current

Forward voltage and reverse current

Beta particles have penetration of about:

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100 times more than that of the gamma particles

100 times less than that of an alpha ray

100 times more than that of an alpha ray

10 times more than that of an alpha particle

What is the resultant force in the diagram shown?

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Zero

6N to left

6N to right

11N to right

Steam engine is:

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An optical system

A thermal system

A thermodynamic system

None of these

Capacitance of a capacitor does not depend upon

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Separation between plates

Thickness of the plates

Area of the plates

Medium between the plates

The magnetic field produced due to the current in a straight wire is proportionalto the :

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Electric current

Conducting material

Length of the wire

Diameter of the wire

There is a certain frequency below which no electrons are emitted from the metal surface, this frequency is known as:

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Critical frequency

Threshold frequency

Maximum frequency

Minimum frequency

When temperature increases, frequency of organ pipe:

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Decreases

Remains the same

Increases

Becomes zero

A force of 6 N act horizontally on a stationary mass of 2kg for 4s. The kineticenergy in joule is

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12

72

56

888

A certain engine coverts 20% of available heat energy into work. Then its efficiency will be:

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20%

80%

50%

None of these

When a person lifts a body from ground work done by lifting force is?

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Positive

Negative

Zero

Half of positive maximum

The equation W = ________𝜟U represents:

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Thermal process

adiabatic process

Isobaric process

None of these

Which one is the case when the wavelength is actually changed?

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When source move relative to observer

When observer move relative to source

When observer moves around a stationary source at the center of circle

When the relative displacement between source and observer is zero

The minimum energy required by an electron to eject from metal surface is known as:

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Photo energy

Critical energy

Threshold energy

Work function

Ultraviolet radiation of 6.2 eV falls on an aluminium surface having work function ∅ = 𝟒. 𝟐 𝒆𝑽.

The kinetic energy of the fastest electron emitted is:

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4 eV

2 eV

2.2 eV

1.2 eV

At the highest point on the trajectory of a projectile, its

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Potential energy is minimum

Kinetic energy is maximum

Total energy is maximum

Kinetic energy is minimum

A body of mass 3 Kg lies on the surface on the table 2m high. It is moved on the surface by 4m. The change of P.E will be:

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Zero

9.8 J

19.6 J

329 J

Bats navigate and find food by:

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Ultrasonic

Echolocation

Refraction

The efficiency of a particle heat engine:

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can be 100%

Cannot be 100%

Is always zero

None of these

You lift a suit case from the floor and keep it on a table. The work done by you on the suitcase does not depend on

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the path taken by the suitcase

weight of the suitcase

initial and final position

None

The method by which only one half of A.C cycle is converted into direct current is called

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half wave amplification

half wave rectification

Full wave rectification

full wave amplification

For a particle in circular motion the centripetal acceleration

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may be more or less than its tangential acceleration

equal to its tangential acceleration a

more than its tangential acceleration

less than its tangential acceleration

The magnetic field due to the electric current in a conducting wire is:

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Towards the centre of the conducting wire

Circular around the conducting wire

In the direction of the electric current

In the direction opposite to the electric current

A diode as a rectifier converts:

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A)c into D)c

D)c into A)c

Varying D)c current into constant D)c current

High voltage into low voltage and vice-versa

How many photons per second does a one-watt bulb emit if its efficiency is 10% and the wavelength of light is 500 nm:

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2.53 × 1017

2.53 × 1019

7.5 × 1019

7.5 × 1017

The de-Broglie wavelength of the particle of mass m and energy E is:

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ℎ

𝜆 = ℎ√2𝑚𝐸

𝜆 = 1

The momentum of a particle is numerically equal to its K.E. What is the velocity of a particle?

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9 ms^-1

3 ms^-1

2 ms-1

1 ms^-1