Question # 1

The pressure exerted on the walls on the vessel by gas molecules is defined as:

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Force per unit volume

Energy per unit area

mass per unit volume

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

When a radioactive nucleus emits a 𝖰 −paritcles, the mass number of the atom:

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Increases by one

Decreases by one

Remains the same

Decreases by four

A bomb of mass 30 kg at rest explodes into two pieces of masses 18 kg and 12 kg. The velocity of 18 kg mass is 6 ms¹ The KE of other mass is

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324 J

256 J

245 J

524 J

The ideal gas obey gas law at:

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Low tempratures and high pressures

High temperatures and low pressures

All temperatures and pressures

None of these

If the radioactive substance reduces to 𝟏 𝟏𝟔 PHYSICS of its original mass in 40 days then its half-life is:

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10days

20days

40days

4days

A satellite moving round the earth constitute

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An inertial frame of reference

Non inertial frame

Neither inertial nor non inertial

Both inertial and non-inertial

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 temperature at which all the gases become liquid is called:

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273 K

-273 K

Absolute Zero

Both (B) and (C)

The minimum energy required to remove an electron is called:

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Stopping potential

Work function

Kinetic energy

None of these

First law of thermodynamics is merely a statement of law of conversation of:

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Energy

Angular momentum

Change

Linear momentum

In photoelectric effect, electrons are emitted with:

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Same energy

Different energies

Both (a) & (b)

Intermittent energies

Truth of kinetic energy theory is confirmed by:

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Diffusion of gases

Brownian motion

Both A and B

None of these

The rate of decay radioactive substance:

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Is constant

Decrease exponentially with time

Varies inversely with time

Decrease linearly with time

The maximum kinetic energy of emitted photoelectrons depends upon:

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The intensity of incident light

Frequency of incident light

Metal surface

Both frequency of incident light and metal surface

The angular momentum changes form 2 units to 6 units in 4s. the torque is

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1 unit

3/2unit

1/2unit

4unit

If velocity time graph is a straight line parallel to time axis then body is

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Moving with zero acceleration

Moving with constant velocity

Covering equal displacement in equal intervals of time

All of these

Torque is necessary for producing.

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angular speed

linear acceleration

angular acceleration

none of these

Bats navigate and find food by:

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Ultrasonic

Echolocation

Refraction

Beta particles have less ionizing power than that of alpha particles because:

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Their smaller energy

Their smaller mass

Their smaller density

Their smaller charge

In photoelectric effect experiment, stopping potential depend upon

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Intensity of light

Frequency of light

Photoelectric current

Both A and B

In photoelectric effect, electrons are emitted:

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Slowly

Intermittently

Both (a) & (b)

Instantly

The nature of thermal radiation is smaller to:

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Ultraviolet rays

Light rays

Both of them

None of these

The frequency and work function of an incident photon are n and𝝋𝟎. If f0 is the threshold frequency, then necessary condition for the emission of photo electron is:

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< 𝑓0

𝑓 ≥ 𝑓0

f = 𝑓0/2

None of these

As the intensity of incident light increases:

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Photoelectric current increases

Photoelectric current decreases

Kinetic energy of emitted photoelectrons increases

Kinetic energy of emitted photoelectrons decreases

The uranium Nucleus 𝟐𝟑𝟖 𝑼 undergoes successive decays, emitting respectively 𝑎 − 𝒓𝒂𝒚,𝖰 − 𝒓𝒂𝒚 𝒂𝒏𝒅 − 𝒓𝒂𝒚𝒔. What is the atomic number and atomic mass of the resulting nucleus:

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90, 238

91, 234

92, 236

92, 238

The specific resistance of a wire varies with its:

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Length

Cross-section

Mass

Material

Vertical component of velocity of the projectile at any instant ‘t’ from the ground is given by:

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𝑣𝑖𝑐𝑜𝑠𝜃

𝑣𝑖𝑐𝑜𝑠𝜃 − 𝑔t

𝑣𝑖𝑠𝑖𝑛𝜃 − 𝑔t

𝑣𝑖𝑠𝑖𝑛𝜃 + 𝑔t

If C_vdonotes molar specific heat at constant volume and𝜟 T is the change in temperature, then C_v𝜟T gives:

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Volume

Pressure

Energy

Entropy

The efficiency of a particle heat engine:

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can be 100%

Cannot be 100%

Is always zero

None of these

Two artificial satellites of unequal masses are revolving in a circular orbit around the earth with a constant speed. Their time periods:

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Will be different

Will depend on their masses

Will be same

Will depend upon the place of their projection

When temperature increases, frequency of organ pipe:

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Decreases

Remains the same

Increases

Becomes zero

If the temperature difference between hot and cold body is greater the heat engine is:

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Not efficient

Less efficient

More efficient

NOne of above

In a gravitational field when work done by gravity is negative then

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P.E increases

P.E decrease

None

P.E remains same

A process in which no heat enters or leaves the system is called.

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Adiabatic process

Isothermal process

Isochoric process

None of these

The temperature scale approved in SI units is:

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Calslus scale

Kelvin scale

Fehrenhelt scale

None of these

Rest mass energy of electron is:

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1.02 MeV

0.51 MeV

931 MeV

200 MeV

Which of the following is a unit of energy?

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unit

whatt

Horse Power

None of the above

The coulomb’s law is valid for the charges which are:

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Moving and point charges

Stationary and point charges

Moving and non-point charges

Stationary and large size charges

According to boyle's law, volume of a given mass of a gas is

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Inversely proportional mass at constant pressure

Directly proportional to pressure at constant temprerature

Inversely proportional pressure at constant temprature

None of these

The number of molecules in one mole of gas is equal to:

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Avogadro number N_A

Gas constant R

Boltzmann constant k

None of these