Tag: the essence of change

Quizzes (5) Questions (143)

Questions Related to the essence of change

Multiple choice physics the essence of change forms of energy and energy conservation energy for everything forms of energy

Hydro-electric power generates

  1. Electrical energy

  2. Nuclear energy

  3. Thermal energy

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hydro-electric power is the process where moving water rotates the turbine. Here potential energy of water converts into kinetic enery of water when waters falls downwards from a height.

After that kinetic energy of water transferred to kinetic energy of turbine and turbine starts rotating. 
After this turbine's kinetic energy is converted into electrical energy and in this way electricity is generated. 
Hence hydro-electric power generates electrical energy.

Multiple choice physics the essence of change forms of energy and energy conservation energy for everything forms of energy

A stretched spring possesses:

  1. kinetic energy

  2. elastic potential energy

  3. electric energy

  4. magnetic energy
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Elastic potential energy is Potential energy stored as a result of deformation of an elastic object, such as the stretching of a spring. It is equal to the work done to stretch the spring, which depends upon the spring constant k as well as the distance stretched.

Multiple choice physics the essence of change forms of energy and energy conservation energy for everything forms of energy

The energy required to raise a given volume of water from a well can be

  1. Mega watts

  2. Mega newton

  3. Mega joules

  4. Kilo watts
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

unit of energy is joule.

so energy required for raising water from the well is also in joule or kilo joule or mega joule.
watt is unit of energy per unit time and  newton is unit of force.
so best option is option C.
Also 1 Mega joule $=10\times10^6$ joule.

Multiple choice physics the essence of change forms of energy and energy conservation energy for everything forms of energy

A cricket ball of mass 300 g is bowled towards a batsman with a speed of $\displaystyle 180\quad km\quad { h }^{ -1 }$. The batsman hits the ball such that it bounces back with the same speed. If the force exerted by the bat on the ball is 3000 N, find the duration of the impact is ____ s.

  1. 1

  2. 0.01

  3. 0.1

  4. 0.04
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Change in momentum = F * t. Initial velocity = 180 km/h = 50 m/s. Final velocity = -50 m/s. Change in momentum = m * (vf - vi) = 0.3 kg * (-50 - 50) = -30 kg m/s. Magnitude = 30. t = 30 / 3000 = 0.01 s.