Physics Practice Question and Answer

Q:

What does an electric dipole experience when it is kept in the non-uniform electric field?

463 0

  • 1
    Only a force
    Correct
    Wrong
  • 2
    Only torque
    Correct
    Wrong
  • 3
    Force and torque both
    Correct
    Wrong
  • 4
    Neither force nor torque
    Correct
    Wrong
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Answer : 3. "Force and torque both"
Explanation :

An electric dipole always experiences a torque when placed in uniform as well as non-uniform electric field. But in non-uniform electric field, dipole will also experience net force of attraction. So the electric dipole in non-uniform electric field experiences both torque and force.


Q:

The capacity of parallel plate condenser is dependent on the

429 0

  • 1
    The separation between the plates
    Correct
    Wrong
  • 2
    The metal used for the construction
    Correct
    Wrong
  • 3
    The thickness of the plate
    Correct
    Wrong
  • 4
    The potential applied across the plates
    Correct
    Wrong
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Answer : 2. "The metal used for the construction"
Explanation :

Therefore, the capacity of a parallel plate capacitor directly depends on the relative permittivity of dielectric material, the permittivity of space, the area of plates, and is inversely dependent on the separation between the plates.

Q:

What happens to the force acting between the charged particles, if the distance between these charged particles is halved?

349 0

  • 1
    It increases by four times
    Correct
    Wrong
  • 2
    It gets doubled
    Correct
    Wrong
  • 3
    It becomes half
    Correct
    Wrong
  • 4
    It reduces by one-fourth
    Correct
    Wrong
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Answer : 1. "It increases by four times "
Explanation :

So, when the distance between the two charges is halved, the force is increased four times.


Q:

What is the constant of proportionality of an oscillator if the damping force is directly proportional to the velocity

382 0

  • 1
    Kg.s-1
    Correct
    Wrong
  • 2
    Kg.m.s-1
    Correct
    Wrong
  • 3
    Kg.s
    Correct
    Wrong
  • 4
    Kg.m.s-2
    Correct
    Wrong
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Answer : 1. "Kg.s-1"
Explanation :

The damping force of an oscillating particle is observed to be proportional to velocity. The constant of proportionality can be measured in. kgs−1.

Q:

Find the molecular mass of a gas that takes three times more time to effuse as compared to He with the same volume

418 0

  • 1
    9 u
    Correct
    Wrong
  • 2
    64 u
    Correct
    Wrong
  • 3
    27 u
    Correct
    Wrong
  • 4
    36 u
    Correct
    Wrong
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Answer : 2. "64 u"
Explanation :

Its molecular mass will be: 64u.

Q:

The coefficient performance of a refrigerator is 5. If the temperature inside the freezer is -20℃, calculate the heat rejected to the surrounding

697 0

  • 1
    110C
    Correct
    Wrong
  • 2

    410C

    Correct
    Wrong
  • 3

    210C

    Correct
    Wrong
  • 4

    310C

    Correct
    Wrong
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Answer : 1. "110C"
Explanation :

A heat pump is a heat engine working in reverse direction. A refrigerator is basically a heat pump, which is used to pump heat (absorbed from materials at lower temperatures inside the refrigerator) to the surroundings at higher temperatures. The coefficient of performance of a refrigerator is defined as the ratio of heat removed

Why

2

Energy from inside the refrigerator per cycle

w

given per cycle for heat removal,

α

,

Why

2

,

w

,

Q:

Which of the following elements has the largest atomic radii?

459 0

  • 1
    Beryllium
    Correct
    Wrong
  • 2
    Lithium
    Correct
    Wrong
  • 3
    Nitrogen
    Correct
    Wrong
  • 4
    Carbon
    Correct
    Wrong
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Answer : 2. "Lithium"
Explanation :

Francium (Fr) has the highest atomic radius in the periodic table. It belongs to the alkali metals group. Its atomic number is 87. The periodic trend of atomic radius suggests that the atomic radius usually decreases along a period (left to right) and increases down a group (top to bottom).

Q:

Which of the following is not a unit of heat?

613 0

  • 1
    Calorie
    Correct
    Wrong
  • 2
    Phon
    Correct
    Wrong
  • 3
    Joule
    Correct
    Wrong
  • 4
    Kcal
    Correct
    Wrong
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Answer : 2. "Phon"
Explanation :

The correct answer is Phon. Phon is not a unit of Heat.

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