IIT-JEE 2000 Screening | Work Power & Energy Question 26 | Physics

IIT-JEE 2000 Screening

MCQ (Single Correct Answer)

-0.5

A wind-powered generator converts wind energy into electrical energy. Assume that the generator converts a fixed fraction of the wind energy intercepted by its blades into electrical energy. For wind speed v, the electrical power output will be proportional to

v²

v³

v⁴

IIT-JEE 1999 Screening

MCQ (Single Correct Answer)

-0.5

A spring of force-constant k is cut into two pieces such that one piece is double the length of the other. Then the long piece will have a force-constant of

$$\left( {{2 \over 3}} \right)k$$

$$\left( {{3 \over 2}} \right)k$$

3 k

6 k

IIT-JEE 1994

MCQ (Single Correct Answer)

-0.25

A particle of mass m is moving in a circular path of constant radius r such that its centripetal acceleration $${a_c}$$ is varying with time t as $${a_c}$$ = k²rt² where k is a constant. The power delivered to the perticles by the force acting on it is:

$$2\pi m{k^2}{r^2}t$$

$$m{k^2}{r^2}t$$

$${{\left( {m{k^4}{r^2}{t^5}} \right)} \over 3}$$

zero

IIT-JEE 1980

MCQ (Single Correct Answer)

-0.5

If a machine is lubricated with oil

the mechanical advantage of the machine increases

the mechanical efficiency of the machine increases

both its mechanical advantage and efficiency increases

its efficiency increases, but its mechanical advantage decreases

PREVIOUS NEXT

JEE Advanced Subjects