Electromagnetism
Current Electricity
MCQ (Single Correct Answer)
Moving Charges and Magnetism
MCQ (Single Correct Answer)
Magnetism and Matter
MCQ (Single Correct Answer)
Electromagnetic Induction
MCQ (Single Correct Answer)
Alternating Current
MCQ (Single Correct Answer)
Electromagnetic Waves
MCQ (Single Correct Answer)
Modern Physics
Dual Nature of Radiation
MCQ (Single Correct Answer)
Semiconductor Devices and Logic Gates
MCQ (Single Correct Answer)
Communication Systems
MCQ (Single Correct Answer)
1
COMEDK 2023 Morning Shift
MCQ (Single Correct Answer)
+1
-0

A thin circular ring of mass ,$$M$$ and radius $$R$$ rotates about an axis through its centre and perpendicular to its plane, with a constant angular velocity $$\omega$$. Four small spheres each of mass $$m$$ (negligible radius) are kept gently to the opposite ends of two mutually perpendicular diameters of the ring. The new angular velocity of the ring will be

A
$$\left(\frac{M+4 m}{M}\right) \omega$$
B
$$\frac{M}{4 m} \omega$$
C
$$\left(\frac{M}{M+4 m}\right) \omega$$
D
$$\left(\frac{M}{M-4 m}\right) \omega$$
2
COMEDK 2023 Evening Shift
MCQ (Single Correct Answer)
+1
-0

A wheel is free to rotate about a horizontal axis through O. A force of $$200 \mathrm{~N}$$ is applied at a point $$\mathrm{P} 2 \mathrm{~cm}$$ from the center $$\mathrm{O}$$. OP makes an angle of $$55^{\circ}$$ with $$\mathrm{x}$$ axis and the force is in the plane of the wheel making an angle of $$25^{\circ}$$ with the horizontal axis. What is the torque?

A
4 N m
B
3.2 N m
C
2 N m
D
3.4 N m
3
COMEDK 2022
MCQ (Single Correct Answer)
+1
-0

A disc of moment of inertia 4 kg - m$$^2$$ revolving with 16 rad/s is placed on another disc of moment of inertia 8 kg - m$$^2$$ revolving 4 rad/s. The angular frequency of composite disc

A
4 rad/s
B
$$\frac{3}{16}$$ rad/s
C
8 rad/s
D
$$\frac{16}{3}$$ rad/s
4
COMEDK 2021
MCQ (Single Correct Answer)
+1
-0

Newton's second law of rotational motion of a system particles having angular momentum L is given by

A
$${{dp} \over {dt}} = {\tau _{ext}}$$
B
$${{dL} \over {dt}} = {\tau _{{\mathop{\rm int}} }}$$
C
$${{dL} \over {dt}} = {\tau _{ext}}$$
D
$${{dL} \over {dt}} = {\tau _{{\mathop{\rm int}} }} + {\tau _{ext}}$$
COMEDK Subjects