Question # 1

The speed of a pendulum is measured to be 3.0 s in the inertial reference frame of the pendulum. What is its period measured by an observer moving at a speed of 0.95 c with respect to the pendulum

Choose an answer

2.9 s

3.0 s

6.6 s

9.6 s

The special theory of relatively treats the problems involving:

Choose an answer

Inertial frames of reference

Non-inertial frames

Non-accelerated frame

Botha (A) and (C)

Both (B) and (C)

From the theory of relativity, momentum p of the photon is related to energy as

Choose an answer

p = hfc

p = hf/c

p = f(hc,f)

p = cf/h

The location and speed anywhere on earth can now be determined using relativistic effects by NAVISTAR to an accuracy of

Choose an answer

2 cm/s

20 cm/s

200 cm/s

2000 cm/s

Practically the quantity v/c is always:

Choose an answer

less than one

Equal to one

Greater then one

all of these

None of these

Due to relative motion of observer and the frame of reference of events, time always:

Choose an answer

Dilates itself

Contracts itself

Stretches itself

Both (A) and (C)

None of these

S.I. unit of planks constant is

Choose an answer

J-s^-1

J.s

J.s^-2

J.s²

Strictly speaking, the earth is:

Choose an answer

An accelerated frame of reference

A non-inertial frame of reference

An inertial frame of reference

^{A non-accelerated frame of reference}

Both (A) and (B)

As the light shines on the metal surface, the electrons are ejected

Choose an answer

slowly

instantaneously

either of these

none of these

The Nobel Prize on the explanation of photoelectric effect was awarded to:

Choose an answer

Max. Planck

Maxwell

Bohr

Rutherford

None of these

A particle of mass 5.0 mg moves with a speed of 8.0 m/s. Its de-Brogile wavelength is

Choose an answer

1.66 m

1.66 x 10^-10m

1.66 x 10^-29cm

1.66 x 10^-29m

The analysis of the distribution of wavelengths of the radiation emitted from a hot body set the foundation of new mechanics, known as

Choose an answer

classical mechanics

Newtonian mechanics

quantum mechanics

statistical mechanics

The mass 'm' of a body moving at 0.8 c (whose rest mass is mo) becomes

Choose an answer

2 mo

1.67 mo

0.67 mo

2.67 mo

If the radius of first orbit of hydrogen atom is 0.53° A the radius of second orbit will be

Choose an answer

2.120°A

0.212°A

21.2°A

0.14°

a

A bar 1.0 m in length and located along x-axix moves with a speed of 0.75 c with respect to a stationary observer. The length of the bar as measured by the stationary observer is

Choose an answer

1.66 m

1.0 m

0.66 m

2.66 m

The energy of a photon is represented by

Choose an answer

h/c²

h/T

hc²

hf/c²

The mass of an object will be doubled at speed

Choose an answer

1.6 x 10⁸ms^-1

2.6 X 10⁸ms^-1

2.6 x 10⁷ms^-1

2.6 x 10⁹ms^-1

The value of the Stephen's constant for black body radiations is given by

Choose an answer

5.6 x 10⁸Wm^-2K^-4

5.67 x 10^-8Wm^-2K^-4

2.9 x 10^-3mK

2.9 x 10³mK

When a platinum wire is heated, it appears white at

Choose an answer

1600°C

900°C

1100°C

1300°C

Albert Einstein got the Nobel prize in physics for his explanation of photoelectric effect in

Choose an answer

1916

1919

1921

1923

Max Planck received the Nobel Prize for his discovery of energy quants in:

Choose an answer

1718 AD

1918 AH

1818 AD

1918 AD

None of these

Electromagnetic radiation or photons interact with matter in

Choose an answer

two distinct ways

three distinct ways

four distinct ways

five distinct ways

In process of annihilation of matter, the two photons produced move in opposite direction to converse

Choose an answer

momentum

charge

energy

mass

The photon of radio-waves has energy of about

Choose an answer

1 Me V

1 Ke v

10^-10e v

10¹⁰e v

Position and momentum of a particle cannot both be measured simultaneously with perfect accuracy. This is the statement of

Choose an answer

photoelectric effect

pair production

Compton effect

uncertainty principle

The Stephen-Boltzmann law for the black body radiation is given by

Choose an answer

E = T²

E = -T²

E = T⁴

E = -T⁴

The idea of quantization of energy was proposed by:

Choose an answer

Einstein

Max.Planck

Maxwell

Bohr

Rutherford

Wave nature of particle was proposed by

Choose an answer

Einstein

Plank

De-Brogile

Max well

Wien's constant is measured in:

Choose an answer

Metre per kelviin

Metre kelvin

Kelvin per meter

Joules

Dynes

Newton's law of motion do not hold in

Choose an answer

an accelerated frame of reference

an unaccelerated frame of reference

both of these

none of these

According to the special theory of relativity

Choose an answer

mass and energy are same entities

mass and energy are same entities but interconverible

mass and energy are different entities but interconverible

mass and energy are different entities but non-interconveritble

More Classes

Other Links

ECAT Pre General Science Physics Chapter 19 Dawn of Modern Physics Online Test MCQs With Answers

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer

Choose an answer