IIT-JEE 1999 Screening | Work Power & Energy Question 27 | Physics

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

Two masses of 1gm and 4 gm are moving with equal kinetic energies. The ratio of the magnitude of their linear momentum is

4 : 1

$$\sqrt 2 :1$$

$$1:2$$

1 : 16

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

JEE Advanced Subjects