Motion in A Plane Test

Question 1
1 / -0

Centripetal acceleration is

A
A constant vector

B
A constant scalar

C
A magnitude changing vector

D
Not a constant vector

Question 2
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When a body is moves in a circular path, no work is done by the force since,

A
There is no displacement

B
There is no net force

C
Force and displacement are perpendicular to each other

D
The force is always away from centre

Question 3
1 / -0

In an atom for the electron to resolve around the nucleus, the necessary centripetal force is obtained from the following force exerted by the nucleus on the electron

A
Nuclear force

B
Gravitational force

C
Magnetic force

D
Electrostatic force

Question 4
1 / -0

In uniform circular motion the velocity vector and acceleration vector are

A
Perpendicular to each other

B
Same direction

C
Opposite direction

D
Not related to each other

Question 5
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The angular velocity of a wheel is 70 rad/sec. If the radius of the wheel is 0.5 m, then linear velocity of the wheel is

A
70 m/s

B
35 m/s

C
30 m/s

D
20 m/s

Question 6
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A body is whirled in a horizontal circle of radius 20 cm. It has angular velocity of 10 rad/sec. What is the linear velocity at any point of circular path?

A
\(10 m/s\)

B
\(20 m/s\)

C
\(2 m/s\)

D
\(\sqrt 2 m/s\)

Question 7
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A tachometer is a device to measure

A
Gravitational pull

B
Speed of rotation

C
Surface tension

D
Tension in a spring

Question 8
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A particle is moving in a circle of radius r with constant speed v, if radius r is double then its centripetal force to keep the same speed should be

A
Doubled

B
Halved

C
Quadrupled

D
Unchanged

Question 9
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The maximum range of a gun on horizontal terrain is 16 km if g = 10 \(m/s^2\). What must be the muzzle velocity of the shell?

A
200 m/s

B
400 m/s

C
100 m/s

D
50 m/s

Question 10
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In the entire path of a projectile the quantity that remains unchanged is

A
Vertical component of velocity

B
Horizontal component of velocity

C
Kinetic energy

D
Potential energy

Question 11
1 / -0

The vector projection of a \(3 \hat{i}+ 4 \hat k\) vector on y-axis is

A
5

B
4

C
3

D
0

Question 12
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The direction of cosines of the vector A are

\(\vec A = 2 \hat i + 4 \hat j - 5\hat k\)

A
\(\frac{2}{\sqrt{45}}, \frac{4}{\sqrt{45}} \,and\, \frac{-5}{\sqrt{45}}\)

B
\(\frac{1}{\sqrt{45}}, \frac{2}{\sqrt{45}} \,and\, \frac{3}{\sqrt{45}}\)

C
\(\frac{4}{\sqrt{45}}, 0\; and\, \frac{4}{\sqrt{45}}\)

D
\(\frac{3}{\sqrt{45}}, \frac{2}{\sqrt{45}} \,and\, \frac{5}{\sqrt{45}}\)

Question 13
1 / -0

A hall has the dimensions (10m) x (12m) x (14m). A fly starting at one corner ends up at a diametrically opposite corner. What is the magnitude of its displacement?

A
17 m

B
26 m

C
36 m

D
20 m

Question 14
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Five equal forces of 10 N each are applied at one point and all are lying in one plane. If the angles between them are equal, the resultant force will be

A
Zero

B
10 N

C
20 N

D
10\(\mathrm{\sqrt 2}\) N

Question 15
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If a unit vector is represented by \(0.5 \hat i + 0.8 \hat j + c \hat k\) then the value of c is

A
\(1\)

B
\(\sqrt{0.11}\)

C
\(\sqrt{0.01}\)

D
\(\sqrt{0.39}\)

Question 16
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How much minimum number of coplanar vectors having different magnitudes can be added to give zero resultant?

A
2

B
3

C
4

D
5

Question 17
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The resultant of vector A x 0 will be equal to

A
zero

B
A

C
zero vector

D
unit vector

Question 18
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Assertion(A): For a projectile the time of flight of a body becomes n times the original value and its speed is made n times.

Reason(R): For a projectile, this is due to the range of the projectile which becomes n times.

(A) Both A and R are true and R is the correct explanation of A.

(B) Both A and R are true but R is not correct explanation of A.

(C) A is true but R is false.

(D) A and R are false.

A
A

B
B

C
C

D
D

Question 19
1 / -0

\(\mathrm{Erg/m^{-1}}\) can be the unit of measure for

A
Force

B
Momentum

C
Power

D
Acceleration

Submit Test

Motion in A Pla...

Question 1

A constant vector

A constant scalar

A magnitude changing vector

Not a constant vector

Question 2

There is no displacement

There is no net force

Force and displacement are perpendicular to each other

The force is always away from centre

Question 3

Nuclear force

Gravitational force

Magnetic force

Electrostatic force

Question 4

Perpendicular to each other

Same direction

Opposite direction

Not related to each other

Question 5

70 m/s

35 m/s

30 m/s

20 m/s

Question 6

\(10 m/s\)

\(20 m/s\)

\(2 m/s\)

\(\sqrt 2 m/s\)

Question 7

Gravitational pull

Speed of rotation

Surface tension

Tension in a spring

Question 8

Doubled

Halved

Quadrupled

Unchanged

Question 9

200 m/s

400 m/s

100 m/s

50 m/s

Question 10

Vertical component of velocity

Horizontal component of velocity

Kinetic energy

Potential energy

Question 11

5

4

3

0

Question 12

\(\frac{2}{\sqrt{45}}, \frac{4}{\sqrt{45}} \,and\, \frac{-5}{\sqrt{45}}\)

\(\frac{1}{\sqrt{45}}, \frac{2}{\sqrt{45}} \,and\, \frac{3}{\sqrt{45}}\)

\(\frac{4}{\sqrt{45}}, 0\; and\, \frac{4}{\sqrt{45}}\)

\(\frac{3}{\sqrt{45}}, \frac{2}{\sqrt{45}} \,and\, \frac{5}{\sqrt{45}}\)

Question 13

17 m

26 m

36 m

20 m

Question 14

Zero

10 N

20 N

10\(\mathrm{\sqrt 2}\) N

Question 15

\(1\)

\(\sqrt{0.11}\)

\(\sqrt{0.01}\)

\(\sqrt{0.39}\)

Question 16

2

3

4