ECAT Pre Computer Science Physics MCQ Test With Answer for Full Book

Referring to the above figure, we can say that of all the elements, the most stable element is

• Phosphours A
• Iron B
• uranium C
• Lithium D
• Bismuth E

The r.m.s value of a.c. current is always

• positive A
• negative B
• zero C
• all of these D

10⁶electrons are moving through a wire per second, the current developed is

• 1.6 x 10^-19 A
• 1 A B
• 1.6 x 10^-15 A C
• 10⁶A D

The range of wavelengths of colurs in the visible colours is

• 140 nm to 456 nm A
• 10 nm to 56 nm B
• 410 nm to 656 nm C
• 910 nm to 956 nm D
• None of these E

The cohesive forces between atoms, molecules or ions in crystalline solids maintain the strict

• short range order A
• long range order B
• both of them C
• none of them D

The A.M. transmission frequency range from

• 500-1000 KHz A
• 540-1600 KHz B
• 300-490 KHz C
• 900-2040 KHz D

The analysis of fluid motion becomes simplified by using

• law of conservation A
• law of conservation of energy B
• both of them C
• none of them D

The product of the pressure and volume of an ideal gas is

• A constant A
• Approximately equal to the universal gas constant B
• Directly proportional to its temperature C
• Inversely proportional to its temperature D

A signal appears after amplification, at the output terminal with a phase shift of 180° , if it is applied at

• inverting input A
• non-inverting input B
• any one of the input terminal C
• none of them D

Three resistors of resistance R each are combined in various ways. Which of the following cannot be obtained?

• 3RΩ A
• 2R/4Ω B
• R/3Ω C
• 2R/3Ω D

Silicon can be obtained from:

• Lead A
• Uranium B
• An isotope of oxygen C
• Sand D

The energy acquired by a mass of 1g moving with the speed of light is

• 3 x 10⁸J A
• 9 x 10¹³J B
• 3 x 10¹³J C
• 9 x 10¹⁶J D

A solenoid is a coil of wire which is:

• Short, loosely wound, cylindrical

  A

• Long, tightly wound, spherical

  B

• Long, loosely wound, cylindrical

  C

• Long, tightly wound, cylindrical

  D

• None of these

  E

The electric flux through any surface depends upon:

• Intensity of electric field

  A

• Area of the surface

  B

• Angle between intensity and area

  C

• All of these

  D

• None of these

  E

Nowadays, Most of the electric energy is produced by the A.C. generators using:

• Hydal water A
• Geothermal energy B
• Solar energy C
• Biomass D
• Both (B) and (D) E

• 5μF A
• 10μF B
• 3μF C
• 6μF D

The phase at the positive peak is

• Π/2 A
• Π B
• 3Π/2 C
• 2Π D

The vibratory or oscillatory motion of a body is

• translatory motion A
• back and forth motion about its mean position B
• free all motion C
• circular motion D

In case of destructive interference of two waves, the amplitude of the resultant wave will be __________ either of the waves.

• Greater than A
• Smaller than B
• Equal to C
• None of these D

The number of protons inside a nucleus is called

• mass number A
• atomic weight B
• atomic number C
• none of these D

The artillery shells travel along parabolic paths under the influence of

• magnetic field A
• electric field B
• electromagnetic field C
• gravitational field D

Which of the following pairs does not have identical dimensions?

• Torque and energy A
• Energy and work B
• Momentum and impulse C
• Mass and moment of inertia D

If the object is placed at 12 cm distance from a convex lens of focal length 6 cm, then we get an image of ____ as that of object:

• Double the size A
• Same size B
• Half the size C
• None of these D

The sum of positive and negative peak values is called:

• Instantaneous value A
• Peak value B
• Rms valuie C
• Peak-to peak-value D
• None of these E

A body falls freely from rest. It covers as much distance in the last second of its motion as covered in the first three seconds. The body has fallen for a time of

• 3 s A
• 5 s B
• 7 s C
• 9 s D

The waveform of alternating voltage is a:

• Square A
• Rectangular B
• Saw-tooth C
• Sinusoidal D
• None of these E

How many isotopes of helium are present?

• 1 A
• 2 B
• 3 C
• 4 D

The three equation of motions are useful only for

• linear motion with increasing acceleration A
• line motion with uniform acceleration B
• linear motion with zero acceleration C
• linear motion with varying acceleration D

Instead of moving the coil towards a magnet, the magnet is moved towards the coil with the same speed. The galvanometer shows current

• Of same magnitude in the same direction A
• Of different magnitude in the same direction B
• Of same magnitude but in opposite direction C
• Of different magnitude in the opposite direction D
• None of these E

In a charged capacitor the energy is stored in

• Both in positive and negative charges A
• Positive charges B
• The edges of the capacitor plates C
• The electric field between the plates D