Laws of Motion Test

Result

Laws of Motion Test - 76

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

If four forces act at a point 'o' as shown in the figure and if O is in equilibrium then the value of '$$\theta $$' & 'p' are

A
$${ 15 }^{ 0 },10\sqrt { 2N } $$

B
$${ 45 }^{ 0 }$$, 10 N

C
40N

D
all the above
Question 2
1 / -0

A simple pendulum has length l. The minimum velocity to be pendulum so that it performs vertical circular motion is

A
$$\sqrt {gl} $$

B
$$\sqrt2{gl} $$

C
$$\sqrt5{gl} $$

D
$$\sqrt {\frac{1}{g}} $$

Solution
Question 3
1 / -0

A bullet of mass $$50$$ gram is fired from a $$5kg$$ gun with a velocity of $$1km/s$$, the speed of recoil of the gun is

A
$$5m/s$$

B
$$1m/s$$

C
$$0.5m/s$$

D
$$-10m/s$$

Solution
Question 4
1 / -0

A rod of mass $$5\ kg$$ is suspended with the help of two strings as shown in figure and remains in equilibrium. Linear mass density of rod is given by $$\mu = \lambda x^n$$ where $$x$$ is distance from left end of the rod. The value of $$n$$ is.

A
$$3$$

B
$$2$$

C
$$5$$

D
$$4$$
Question 5
1 / -0

A cyclist is riding at a speed of $$ 14 \sqrt { 3 } m/s $$ and takes a turn around a circular road of radius $$ 20\sqrt { 3 } m $$. Its inclination to the vertical is

A
$$ 30^0 $$

B
$$ 40^0 $$

C
$$ 60^0 $$

D
$$ 70^0 $$

Solution
Question 6
1 / -0

A circular coil radius 4 cm having 50 turns carries a current of 2A. it is placed in a uniform magnetic field of intensity 0.1 T. the work done to rotate the coil from the equilibrium position through $${ 180 }^{ \circ }$$ is

A
$$\dfrac { 16\pi }{ 500 } J$$

B
$$\dfrac { 64\pi }{ 175 } J$$

C
$$\dfrac { 4\pi }{ 125 } J$$

D
$$\dfrac { 2\pi }{ 25 } J$$

Solution
Question 7
1 / -0

If the action and reaction forces are always equal in magnitude, then these forces

A
will produce accelerations of equal magnitudes.

B
may not produce accelerations of equal magnitudes.

C
produce velocities of equal magnitudes.

D
will not produce accelerations of equal magnitudes

Solution

According to newton's 3rd law of motion, Every action has equal and opposite reaction. Action and reaction always act in pairs, and on different bodies.
Let two masses $$m_1$$ and $$m_2$$ are pairs of masses applying force on each other ie $$F$$.
Acceleration of masses will be $$a_1=\dfrac F{m_1}$$ and $$a_2=\dfrac F{m_2}$$ Hence acceleration of masses also depends on the mass.
So, these forces may not produce accelerations of equal magnitudes.
Question 8
1 / -0

A bullet of mass $$m$$ and speed $$v$$ hits a pendulum bob of mass $$M$$ at time $$t _ { 1 }$$ and passes completely through the bob. The bullet emerges at time $$t _ { 2 }$$ with a speed of $$v / 2$$. The pendulum bob is suspended by a stiff rod of length $$l$$ and negligible mass. After the collision, the bob can barely swing through a complete vertical circle.At time $$t _ { 3 }$$ , the bob reaches the highest position.What quantities are conserved in this process?

A
Total kinetic energy of the bob and the bullet during the time interval $$\Delta t = t _ { 2 } - t _ { 1 }$$

B
Total momentum of the bob and the bullet during the time interval $$\Delta t = t _ { 2 } - t _ { 1 } $$

C
Total mechanical energy of the bob and the bullet during the time interval $$t _ { 3 } - t _ { 1 } $$

D
Momentum of the bob after $$t _ { 2 }$$

Solution
Question 9
1 / -0

A wire of density $$\rho $$and cross-sectional area A forms three side of a square and is free to rotate the horizontal axis $${ OO }^{ 1 }.$$ A magnetic field B exists in the vertically upward direction. When a current k is passed through the wire, the system comes to equilibrium at angle $$\theta $$ to the vertical.Then the value of $$\theta $$ is given by.

A
$$cos\theta =\dfrac { 2A\rho g }{ iB } $$

B
$$cot\theta =\dfrac { 2A\rho g }{ iB } $$

C
$$tan\theta =\dfrac { A\rho g }{ 2iB } $$

D
$$sin\theta =\dfrac { A\rho g }{ 2iB } $$

Solution
Question 10
1 / -0

A write of density $$p$$ and cross-sectional area A forms three sides if a square and is free to rotate about the horizontal axis $${ OO }^{ 1 }$$. A magnetic field B exist in the vertically upward direction. When a current i is passed through the wire, the system come to equilibrium at angle $$\theta $$ to the vertical. Then the value if $$\theta $$ is given by

A
$$\cos { \theta } =\dfrac { 2Apg }{ iB } $$

B
$$\cot { \theta } =\dfrac { 2Apg }{ iB } $$

C
$$\tan { \theta } =\dfrac { Apg }{ 2iB } $$

D
$$\sin { \theta } =\dfrac { Apg }{ 2iB } $$

Solution