CBSE Questions for Class 11 Medical Physics Work, Energy And Power Quiz 4 - MCQExams.com

A force $$F=(2+x)$$ acts on a particle in x-direction where $$F$$ is in newton and $$x$$ in meter. Find the work done by this force during a displacement from $$x=1.0$$ m to $$x=2.0\ m$$.
  • $$3.5 \ J$$
  • $$7 \ J$$
  • $$4.5 \ J$$
  • $$5.5 \ J$$
A force $$\displaystyle \vec{F}= \left ( 3t\hat{i}+5\hat{j} \right )N$$ acts on a body due to which its displacement varies as $$\displaystyle \vec{S}= \left ( 2t^{2}\hat{i}-5\hat{j} \right )m.$$ Work done by this force in 2 second is:
  • 32 J
  • 24 J
  • 46 J
  • 20 J
Equal net forces act on two different blocks A and B of masses m and 4m respectively. For same displacement, identify the correct statement.
  • Their kinetic energies are in the ratio $$\displaystyle \frac{K_{A}}{K_{B}}= \frac{1}{4}$$
  • Their speeds are in the ratio $$\displaystyle \frac{v_{A}}{v_{B}}= \frac{1}{1}$$
  • Work done on the blocks are in the ratio $$\displaystyle \frac{W_{A}}{W_{B}}= \frac{1}{1}$$
  • All of the above
A block of mass $$M$$ is hanging over a smooth and light pulley through a light string. The other end of the string is pulled by a constant force $$F$$. The kinetic energy of the block increases by $$40$$ $$J$$ in $$1 $$ $$s$$. The tension in the string is:
  • $$F$$
  • $$Mg$$
  • $$F+Mg$$
  • $$F-Mg$$
A particle of mass $$m$$ moves on a straight line with its velocity varying with the distance travelled according to the equation $$\displaystyle v= \alpha \sqrt{x},$$ where a is a constant. Find the total work done by all the forces during a displacement from $$x=0$$ to $$x=d$$.
  • $$\displaystyle \frac{1}{2}ma ^{2}b$$
  • $$\displaystyle \frac{1}{4}ma ^{2}b$$
  • $$ma ^{2}b$$
  • $$2\ ma ^{2}b$$
A player kicks a ball of mass 250 g at the centre of a field. The ball leaves his foot with a speed of 10 m/s. Find the work done by the player on the ball.
  • $$10.5 \:J$$
  • $$12.5 \:J$$
  • $$1.5 \:J$$
  • $$2.5 \:J$$
A block is constrained to move along x-axis under a force F=-2x. Here, F is in newton and x in metre. Find the work done by this force when the block is displaced from x=2 m to x=-4 m.
  • -4 J
  • -8 J
  • -12 J
  • -16 J
Calculate the work required to be done to stop a car of 1500 kg moving at a velocity of $$60 \:kmh^{-1}$$
  • $$-208333 \:J$$
  • $$208333 \:J$$
  • $$-209333 \:J$$
  • $$-207333 \:J$$
Certain force acting on a 20 kg mass changes its velocity from $$5 \:ms^{-1}$$ to $$2 \:ms^{-1}$$. Calculate the work done by the force.
  • $$-210 \:J$$.
  • $$210 \:J$$.
  • $$-105 \:J$$.
  • $$420 \:J$$.
An object of mass, m is moving with a constant velocity v. How much work should be done on the object in order to bring the object to rest ?
  • $$-\dfrac{1}{2}mv^2$$
  • $$\dfrac{1}{2}mv^2$$
  • $$-mv^2$$
  • $$-\dfrac{1}{2}mv$$
A block is constrained to move along x-axis under a force $$\displaystyle F= \frac{4}{x^{2}}\left ( x\neq 0 \right ).$$ Here, F is in newton and x in metre. Find the work done by this force when the block is displaced from x=4 m to x=2 m.
  • -1 J
  • -2 J
  • -3 J
  • -4 J
A block of mass 30 kg is being brought down by a chain. If the block acquires a speed of 40 cm/s in dropping down 2 m. Find the work done by the chain during the process. $$\displaystyle \left ( g= 10 m/s^{2} \right )$$
  • -297.6 J
  • -375 J
  • -597.6 J
  • -674.6 J
A bullet of mass 20 g moving with a velocity of 500 m/s, strikes a tree and goes out from the other side with a velocity of 400 m/s. Calculate the work done by the bullet (in joules) in passing through the tree.
  • $$900 \:J$$
  • $$800 \:J$$
  • $$950 \:J$$
  • $$500 \:J$$
Sania, a high-board diver of mass 50 kg is diving from a height of 30 m into a pool (see figure given). What is the potential energy of Sania at point A ? $$(g=10 \:m \:s^{-2})$$

246313_f049ad05e7424cd698a304b08679cf1a.png
  • $$5000 J$$
  • $$10000 J$$
  • $$15000 J$$
  • $$20000 J$$
Energy associated with moving objects is called:
  • Potential energy
  • Kinetic energy
  • No energy
  • Work
Flowing water possess same energy as :
  • Water in a water tank
  • A stationery object
  • Flowing air
  • None of these
Water stored in a dam primarily possesses
  • Heat energy
  • Electrical energy
  • Kinetic energy
  • Potential energy
The gravitational potential energy possessed by a body is by virtue of its _________.
  • position
  • velocity
  • acceleration
  • temperature
A car is accelerated on a levelled road and attains a velocity 4 times of its initial velocity. In this process, the potential energy of the car
  • does not change
  • becomes twice of initial
  • becomes 4 times of initial
  • becomes 16 times of initial
Which of the following is an example of an object with Kinetic Energy?
  • Watch spring
  • Bent bow
  • Stone at a height
  • Car moving along the road
The moving striker of the carom board will possess------ energy
  • Kinetic
  • Potential
  • Solar
  • Electric
Potential energy of a body depends on its:
  • motion
  • colour
  • mass
  • none of these
Which one of the following possesses potential energy?
  • Moving vehicle on the road
  • A running athlete
  • Stone on the road
  • A stretched rubber band
An overhead tank having some water possesses .......... energy.
  • Kinetic
  • Potential
  • Thermal
  • Electrical
Energy possessed by a body by virtue of its motion is :
  • Potential energy
  • Kinetic energy
  • Chemical energy
  • Electrical energy
A student sitting at the top of a tree has ............ than the student who is sitting on the ground.
  • less potential energy
  • more potential energy
  • more kinetic energy
  • more gravitational energy
The energy directly related to the speed of a moving body and its mass is:
  • Kinetic
  • Potential
  • Solar
  • Electric
Energy possessed by a body by virtue of its position at a height is :
  • Kinetic energy
  • Chemical energy
  • Potential energy
  • Magnetic energy
A heavy object has ---- potential energy than a lighter one
  • Less
  • More
  • Same
  • None of these
Two weights of 5 kg and 10 kg are placed on a horizontal table of height 1.5 m. Which will have more potential energy?
  • 5 kg
  • 10 kg
  • Both will have equal energy
  • None of the above
A solar cell converts solar energy into:
  • Chemical energy
  • Light energy
  • Electrical energy
  • Muscular energy
From the following statements find the one that is NOT correct:
  • A flying bird has both potential and kinetic energy.
  • A ball rolling on the ground has kinetic energy but no mechanical energy.
  • A stretched rubber band has potential energy
  • Chemical energy can be converted into electrical energy
The form of energy that wood can be categorized into is:
  • chemical energy
  • electrical energy
  • potential energy
  • muscular energy
An atom bomb converts __________ into heat and sound energy.
  • electrical energy
  • heat energy
  • mechanical energy
  • atomic energy
Law of conservation of energy states that:
  • energy cannot be destroyed but can be created and transformed from one form to another
  • energy exists in only one form
  • energy exists in many forms but it cannot be transformed
  • energy can neither be created nor be destroyed but can be transformed from one form to another
The form of energy present in a wound spring is:
  • chemical
  • heat energy
  • magnetic
  • mechanical
A wound spring has:
  • chemical energy
  • magnetic energy
  • mechanical energy
  • muscular energy
A ball of mass 3 kg collides with a wall with velocity $$10\:m/sec$$ at an angle of $$30^{\circ}$$ with the wall and after collision reflects at the same angle with the same speed. The change in momentum of ball in MKS unit is-
  • 20
  • 30
  • 15
  • 45
Two identical 5 kg blocks are moving with same speed of $$2\:m/s$$ towards each other along a friction-less horizontal surface. The two blocks collide, stick together and come to rest. Consider two blocks as a system, the work done on the system by the external forces will be:
  • $$20 $$ Joule
  • $$-20 $$ Joule
  • $$0$$ Joule
  • None of these
A position dependent force $$F=7-2x+3x^{2}$$N acts on a small object of mass 2kg to displace it from $$x=0$$ to $$x=5m$$. The work done in joules is-
  • 70
  • 270
  • 35
  • 135
A box of mass $$1\ kg$$ is pulled on a horizontal plane of length $$1\ m$$  by a force of $$8\ N$$  then it is raised vertically to a height of $$2$$ m, the net work done is:
  • 28 J
  • 8 J
  • 18 J
  • none of the above
A particle of mass $$m_{1}$$ moving with a velocity of $$5m/s$$ collides head on with a stationary particle of mass $$m_{2}$$. After collision both the particle move with a common velocity of $$4m/s$$, then the value $$m_
{1}/m_{2}$$ is:
  • 4:1
  • 2:1
  • 1:8
  • 1:2
A force of $$10$$ N acts on a body of $$2$$ kg mass for a distance of $$1$$ m. The kinetic energy received by the body is:
  • 20 J
  • 10 J
  • 5 J
  • 2.5 J
A time dependent force F = 10 t is applied on 10 kg block. Find out the work done by F in 2 seconds.
  • 40 J
  • 20 J
  • 120 J
  • 60 J
Force shown acts for $$2$$ seconds. Find out work done by force $$F$$ on $$10$$ kg in $$3$$ seconds.
301887_761b4a987fc1439fa0f106fe720cb995.png
  • 30 J
  • 20 J
  • 50 J
  • 60 J
A force acts on a $$3$$ gm particle in such a way that the position of the particle as a function of time is given by $$x=3t-4t^2+t^3$$, where x is in meters and t is in seconds. The work done during the first $$4$$ second is:
  • $$384 mJ$$
  • $$168 mJ$$
  • $$528 mJ$$
  • $$541 mJ$$
Two bodies P and Q of equal masses are kept at heights $$x$$ and $$4x$$ respectively. What will be the ratio of their potential energies?
  • $$1:8$$
  • $$4:1$$
  • $$1:4$$
  • $$8:1$$
What is work done in holding a body of mass $$20\ kg$$ at a height of $$2\ m$$ above the ground? $$(g = 10\ m/s^2)$$
  • $$40\ J$$
  • $$400\ J$$
  • $$10\ J$$
  • Zero
The diagrams represent the potential energy U as a function of the inter-atomic distance r. Which diagram corresponds to stable molecules found in nature.
The work done by the frictional force on a surface in drawing a circle of radius r on the surface by a pencil of negligible mass with a normal pressing force N (coefficient of friction $$\mu_k$$ ) is : 
  • $$4\pi r^{2} \mu_K N$$
  • $$-2\pi r^{2} \mu_K N$$
  • $$-2\pi r \mu_K N$$
  • Zero
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 11 Medical Physics Quiz Questions and Answers