Work And Energy Test

Work And Energy

This is Work and Energy Test-01 for CBSE class 09 Science.. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
Work done by centripetal force is
  • A
    >0
  • B
    ≥0
  • C
    <0
  • D
    0
    Correct
2
For what value of .\(\phi \). is work done maximum?
  • A
    \({0^0}\)
    Correct
  • B
    \({\text{6}}{0^0}\)
  • C
    \({\text{4}}{{\text{5}}^0}\)
  • D
    \({\text{9}}{0^0}\)
3
1k w h =?
  • A
    \({\text{3}}.{\text{6 }} \times {\text{ 1}}{0^{\text{6}}}{\text{ }}\)J
    Correct
  • B
    \({\text{3}}.0{\text{6 }} \times {\text{ 1}}{0^{\text{4}}}{\text{J }}\)
  • C
    4.2J
  • D
    \({\text{36 }} \times {\text{ 1}}{0^{\text{6}}}{\text{J }}\)
4
1 W. S = ________?
  • A
    1 joule
    Correct
  • B
    10 joule
  • C
    \({\text{3}}.{\text{6 }} \times {\text{ 1}}{0^{{\text{6 }}}}\)joule
  • D
    2 joule
5
A certain household has consumed 250 units of energy during a month. How much energy is this in joules?
  • A
    \({\text{9 }} \times {\text{1}}{0^{\text{6}}}{\text{J }}\)
  • B
    \({\text{1}}0{\text{ }} \times {\text{ 1}}{0^{\text{5}}}{\text{Joule }}\)
  • C
    \({\text{9 }} \times {\text{1}}{0^{\text{8}}}{\text{J }}\)
    Correct
  • D
    \({\text{5 }} \times {\text{ 1}}{0^{\text{8}}}{\text{ }}\)Joule
6
1 meV (mega electron volt) is equal to
  • A
    \({\text{1}}.{\text{6 }} \times {\text{ 1}}{0^{{\text{13}}}}{\text{J }}\)
  • B
    \({\text{1}}.{\text{6 }} \times {\text{1}}{0^{{\text{19}}}}{\text{J }}\)
  • C
    \({\text{1}}.{\text{6}} \times {\text{1}}{0^{ - {\text{13}}}}{\text{J }}\)
    Correct
  • D
    \({\text{1}}.{\text{6 }} \times {\text{1}}{0^{ - {\text{19}}}}{\text{J }}\)
7
9800 joule of energy was spent to raise a mass of 50kg, the mass was raised to a height of
  • A
    none of these
  • B
    20m
    Correct
  • C
    980m
  • D
    10m
8
A machine does 2000 joule of work in 400 seconds. What is the power of machine?
  • A
    0.5w
  • B
    5w
    Correct
  • C
    6w
  • D
    20w
9
Calculate the time taken by a 150 w bulb of consuming 3000 joule of energy.
  • A
    30 s
  • B
    25 s
  • C
    20s
    Correct
  • D
    40 s
10
What is the work done to be done to increase the velocity of a car from \({\text{3}}0{\text{km }}{{\text{h}}^{ - {\text{1}}}}{\text{ }}\)to 60 \({\text{km}}{{\text{h}}^{ - {\text{1}}}}{\text{ }}\)if the mass of the car is 1500kg?
  • A
    15637j
  • B
    16537j
  • C
    16535j
  • D
    none of these
    Correct
11
What is the force required to lift a block of mass 2m?
  • A
    \(\frac{3}{2}mg\)
  • B
    2mg
    Correct
  • C
    \(\frac{{mg}}{2}\)
  • D
    mg
12
A body of mass 20kg climbs up 20 steps of the stairs in 20 seconds. If each step is 20cm high. What is the power used in climbing the stairs (\({\text{g}} = {\text{1}}0{\text{m/}}{{\text{s}}^{\text{2}}}\))
  • A
    20w
  • B
    40w
    Correct
  • C
    400w
  • D
    200w
13
The angle between force and displacement is 2 Q. forwhat value of Q is work done zero?
  • A
    \({\text{3}}{0^0}\)
  • B
    \({\text{9}}{0^0}\)
  • C
    \({\text{18}}{0^0}\)
  • D
    \(\;{\text{4}}{{\text{5}}^0}\)
    Correct
14
Two persons P and Q do same amount of work. The person Q does the work in \({t_p}\) seconds and person Q in \({t_q}\)seconds. Find the ratio of power delivered by them.
  • A
    1
  • B
    zero
  • C
    \(\frac{{{t_Q}}}{{{t_P}}}\)
    Correct
  • D
    \(\frac{{tP}}{{tQ}}\)
15
Statement A: Work is said to be done when a camel is carrying a load on its back Statement B: Work is said to be done when a sailboat is moving due to wind energy Which of the above statement is true?
  • A
    none of these
  • B
    both a and b
  • C
    statement B
    Correct
  • D
    statement A