MCQ-1-Test-Class-12-MHTCET-Physics-Chapter-9-Rotational Dynamics

Select which one is correct

Q1. The angular velocity of the earth will be

(a) (2π/86400) rad s^-1        (b) (3π/86400) rad s^-1

(c) (π/86400) rad s^-1          (d) (2π/43200) rad s^-1

Select which one is correct

Q2. A particle moves in a circular path of radius 0.5 m with a linear speed of 2 ms^-1, its angular speed is

 (a) 2 rad s^-1                    (b). 3 rad s^-1           (c) 4 rad s^-1         (d) None of these

Select which one is correct

Q3. The minute hand of a clock is 10 cm long. The linear speed of its tip is

a. 1.643 x 10^-4 ms^-1          b. 1.876 x 10^-4 ms^-1

c. 1.744 x 10^-4 ms^-1          d. 1.502 x 10^-4 ms^-1

Select which one is correct

Q.4 A grindstone is found to have a angular speed of 150 rpm, 10 s after starting from rest. The angular acceleration of the grindstone

a. π/3        b. π/2

c. π/6        d. π/5

Select which one is correct

Q.5 The angular velocity of a particle is given by the equation ω = 2t² +5 rad s^-1. Find out the instantaneous angular acceleration at t = 4s.

 a. 16 rad s^-2        b.19 rad s^-2

c.10 rad s^-2         d.12 rad s^-2

Select which one is correct

Q6. A particle moves in a circle of radius 2 cm at a speed given by v= 4t, where v is in cms^-1 and t in second.

Find the tangential acceleration at t=1s and total acceleration at t=1s.

 a. 6 cms^-2 and 5 cms^-2 b. 4 cms^-2 and 4x(5)^1/2 cms^-2

c. 5 cms^-2 and 5x(5)^1/2 cms^-2 d. None of these

Select which one is correct

Q7. A particle is moving on a circular path of radius 0.3 m and rotating at 1200 rpm. The centripetal acceleration of the particle is

 a. 4732.60 ms^-2    b. 47.3260 ms^-2

c. 4.73260 ms^-2    d. 473.260 ms^-2

Select which one is correct

Q8. An artificial satellite of mass 2500 kg is orbiting around the earth with a speed of 4kms^-1 at a distance of 10⁴ km from the earth. The centripetal force acting on it is.

 a. 4 kN       b. 6 KN        c. 8 kN      d. 2 kN

Select which one is correct

Q.9 A car is moving in a circular horizontal track of radius 10 m with a constant speed of a 10 ms^-1. A plump bob is suspended from the roof of the car by a light rigid rod of length 100 m. The angle made by the rod with the vertical will be

 a. 60°     b. 30°

c. 45°    d. zero

Select which one is correct

Q.10 Find the maximum speed at which a car can turn round a curve of 30 m radius on a level road, if the coefficient of friction between the tyres and the road is 0.4. (Given, acceleration due to gravity = 10 ms^-1)

a. 12 ms^-1    b.10 ms^-1

c. 11 ms^-1    d. 15 ms^-1

Select which one is correct

Q.11 A circular race track of radius 300 m is banked at angle of 15°. If the coefficient of friction between the wheels of a race car and the road is 0.2, what is the maximum permissible speed to avoid slipping?

[Take, tan 15° = 0.2679]

 a. 49.2 ms^-1    b. 38.1 ms^-1

c. 36.3 ms^-1   d. 48.3 ms^-1

Select which one is correct

Q.12 Consider a bob whose upper end is fixed with length of 2 m is given with a horizontal push through angular displacement of 60°. Find the angular velocity of the bob, if it is of 2 kg. [Take, g=10ms^-2]

 a. 10^1/2 rad s^-1     b. 20^1/2  rad s^-1

 c.  8^1/2 rad s^-1       d. None of these

Select which one is correct

Q.13 Length of a simple pendulum is 2 m and mass of its bob is 0.2 kg. If the tension in the string exceeds 4 N, it wll break. If g =10 ms^-2 and the bob is whirled in a horizontal plane, the maximum angle through which the sting can make with vertical during rotation is.

 a. 40°          b. 60°       c. 50°      d. 180°

Select which one is correct

Q.14 A weightless thread can withstand tension upto 30N. A stone of mass 0.5 kg is tied to it and is revolved in a circular path of radius 2 m in a vertical plane. If g=10 ms^-2 then find the maximum angular velocity of stone.

 a. 4 rads^-1     b. 5 rads^-1       c. 6 rads^-1        d. 7 rads^-1         

Select which one is correct

Q.15 A stone is whirled in a vertical circle at the end of a rope of length 0.5 m. Find the velocities of the stone at lowest and highest points to just complete the circle. (Take, g =9.8 ms^-2)

 a. 4.949 and 2.213 ms^-1     b. 5.921 and 3.312 ms^-1

c. 1.235 and 2.312 ms^-1      d. None of these

Select which one is correct

Q.16 A wheel is rotating at 900 rpm about its axis. When the power is cut off, it comes to rest in 1 min. The angular retardation in rad s^-2 is

 a. π/2      b. π/4       c. π/6      d. π/8