R4RIN – MCQs, Mock Tests | ECAT ECAT Physics Circular Motion Mcqs Questions Set 2

The rotational K.E of hoop is equal to the

1. its translational K.E
2. half than its translational K.E
3. double than its translational K.E
4. four times than its translational K.E

✅ Correct Answer: 1

A hoop and disc have same mass and radius. Their rotational K.E are related by an equation

1. K.Ehoop = K.Edisc
2. K.Ehoop = 2K.Edisc
3. K.Ehoop = 1/2K.Edisc
4. K.Ehoop = 4K.Edisc

✅ Correct Answer: 2

The critical speed of an artificial satellite is

1. 8 Kms-1
2. 8.1 Kms-1
3. 7.9 Kms-1
4. 8 ms-1

✅ Correct Answer: 3

Geo-stationary satellite completes one rotation around earth in

1. 3 hours
2. 6 hours
3. 12 hours
4. 24 hours

✅ Correct Answer: 4

Radius of geo-stationary orbit from center of earth is nearly

1. 42000km
2. 36000km
3. 24000 km
4. 18000 km

✅ Correct Answer: 1

According to Einstein the gravity interaction is possible between

1. material objects only
2. material objects and electromagnetic radiation only
3. electromagnetic radiations
4. none of the above

✅ Correct Answer: 2

One radian is equal to

1. 67.3?
2. 57.3?
3. 87.3?
4. 60?

✅ Correct Answer: 2

The period of a circular motion is given by

1. T = rV
2. T = ?w
3. T = 2??
4. T = 2?/?

✅ Correct Answer: 4

The direction of linear velocity of body moving in a circle is

1. along the axis of rotation
2. along the tangent
3. directed towards the center
4. directed away form the center

✅ Correct Answer: 2

When a body moves in a circle the angle between its linear velocity and angular velocity is always

1. 180?
2. 0?
3. 90?
4. 45?

✅ Correct Answer: 3

The circumference subtends an angle

1. radianradian
2. 2? radian
3. ?/2 radian
4. 4? Radian

✅ Correct Answer: 2

The relation between linear and angular acceleration is

1. a = a x r
2. a = r x a
3. a = a x r
4. r = a x a

✅ Correct Answer: 3

When a body is whirled in a horizontal circle by means of a string the centripetal force is supplied by

1. mass of a body
2. velocity of body
3. tension in the string
4. centripetal acceleration

✅ Correct Answer: 3

Centripetal force performs

1. maximum work
2. minimum work
3. negative work
4. no work

✅ Correct Answer: 4

When a body moves in a circle of radius r with linear speed V its centripetal force is

1. mV/r2
2. mV/r
3. mV2/r
4. mV2/r2

✅ Correct Answer: 3

A stone is whirled in a vertical circle at the end of a string. When the stone is at the highest position the tension in the string is

1. maximum
2. zero
3. equal to the weight of the stone
4. less than the weight of the stone

✅ Correct Answer: 3

The span of broad jump depends upon

1. mass of the jumper
2. height of jump
3. angle of projection
4. none

✅ Correct Answer: 3

In case of planets the necessary acceleration is provided by

1. Gravitational force
2. frictional force
3. coulomb force
4. centripetal force

✅ Correct Answer: 1

If a car moves with a uniform speed of 2 ms-1 in a circle of radius 0.4. Its angular speed is

1. 4 rad. S-1
2. 5 rad. S-1
3. 1.6 rad. S-1
4. 2.8 ms-1

✅ Correct Answer: 2

A body can have consutant velocity when it follows a

1. elliptical path
2. circular path
3. parabolic path
4. rectilinear path

✅ Correct Answer: 4

A body moving along the circumference of a circle completes two revolutions. If the radius of the circular path is R the ration of displacement to the covered path will be

1. ? R
2. 2? R
3. zero
4. 4? R

✅ Correct Answer: 3

The angular speed for daily rotatio of earth in rad S-1 is

1. 2 ?
2. ?
3. 4 ?
4. 7.3 x 10-5 rads-1

✅ Correct Answer: 4

When a wheel 1 m in diameter makes 30 rev min the linear speed of point on its rim in ms-1 is

1. 2?
2. ?/2
3. ?
4. 20?

✅ Correct Answer: 2

A cyclist cycling around a circular racing track skids because

1. the centripetal force upon him is less than limiting friction
2. the centripetal force upon him is greater then limiting friction
3. the centripetal force upon him is equal to the limiting friction
4. the friction between the tyres of the cycle and road vanishes

✅ Correct Answer: 2

If a wheel of radius r turns through an angle of 30? then the distance through which any point on its rim moves is

1. ? /3 x r
2. ?/6 x r
3. ?/30 x r
4. ? / 180 x r

✅ Correct Answer: 2

In angular motion Newtons second law of motion is

1. F=ma
2. F=?p/?t
3. ? = 1a
4. all above

✅ Correct Answer: 3

Angular speed of seconds hand of a watch in rads-1 is

1. ?
2. ?/2
3. ?/30
4. ?/180

✅ Correct Answer: 3

The shaft of a motor rotates at a constant angular speed of 360rev/min. Angle turned through in 1 sec in radian is

1. ?
2. 3?
3. 6?
4. 12?

✅ Correct Answer: 4

What is outward force acting on a mass of 10 kg when rotating at one end an inelastic string 10m long at speed of 1m/s?

1. 1N
2. 10N
3. 2N
4. 100N

✅ Correct Answer: 1

If we whirl a stone at the end of a string in the vertical circle it is likely to break when the stone is

1. at the highest point
2. at the lowest point
3. at any point during motion
4. at the point where gravity is not acting

✅ Correct Answer: 2

moving along the circumference of a circle completes two revolutions. If the radius of the circular path is R the ratio of displacement to the covered path will be

1. ??R
2. 2??R
3.
4. 4??R

✅ Correct Answer: 3

A man of weight W is standing on an elevator which is ascending with an acceleration a. The apparent weight of the man is

1. mg
2. mg - ma
3. mg + ma
4. mg - ma

✅ Correct Answer: 3

Who discovered the inverse square law for gravity?

1. Einstein
2. Galileo
3. Newtons
4. Plank

✅ Correct Answer: 3

The planet nearest to the earth is

1. Venus
2. Mercury
3. Uranus
4. Sun

✅ Correct Answer: 1

A satellite moving round the earth constitutes

1. An inertial frome of reference
2. non inertial frame
3. neither inertial nor non inertial
4. both inertial and non inertial

✅ Correct Answer: 2

Minimum number of communication satellites required to cover the whole carth is

1. 4
2. 3
3. 2
4. 5

✅ Correct Answer: 2

A body of 2 kg is suspended form the ceiling of an elevator moving up with an acceleration g. Its apparent weight in the elevator will be

1. 9.8 N
2. 19.6 N
3. 129.4 N
4. 39.2 N

✅ Correct Answer: 4

If a body of mass 10 kg is allowed to fall freely its weight becomes

1. zero
2. 89N
3. 9.8 N
4. 10N

✅ Correct Answer: 1

How many days would be in a year if the distance between the earth and the sun were reduced to half of its present value (assuming circular orbit)?

1. 365 days
2. 730 days
3. 329 days
4. 129 days

✅ Correct Answer: 4

When a body is moving along a circular path it covers a certain angle in a given internal of time. Such type of motion is

1. vibratory motion
2. linear motion
3. rotatory motion
4. angular motion

✅ Correct Answer: 4