1st Year Physics Chapter 2 TestForce and Motion

Q1. Multiple choice questions (Attempt all · 10 × 1 = 10)

1. If cross product of two vectors x points along positive z-axis, then the vectors  and  must lie in:

   1. yz-plane

   2. xz-plane

   3. zy-plane

   4. No plane

2. When an object is in free fall, what force is acting on it (Neglecting air resistance)?

   1. Frictional force

   2. Magnetic force

   3. Gravitational force

   4. Electric force

3. The projectile gains its maximum height at an angle of:

   1. 0^o

   2. 45^o

   3. 60^o

   4. 90^o

4. A body having uniform acceleration of 10ms^-2 has the velocity of 100ms^-1. In what time its velocity will be double?

   1. 8s

   2. 10s

   3. 12s

   4. 14s

5. If a shell explodes in midair, its fragments fly off in different directions. The total momentum of fragments:

   1. Decrease

   2. Increase

   3. Becomes zero

   4. Remains the same

6. In two dimensional inelastic collision, which of the following is always conserved?

   1. Total K.E

   2. Linear momentum in both x and y direction

   3. Angular momentum

   4. Speed of each object

7. When two vectors are antiparallel, the angle between them is:

   1. Zero

   2. 90^o

   3. 180^o

   4. 270^o

8. A car starts from rest and covers a distance of 100m in one second with uniform acceleration. Its acceleration is:

   1. 50ms^-2

   2. 100ms^-2

   3. 200ms^-2

   4. 300ms^-2

9. The resultant of two forces of 30N and 40N acting parallel to each other and in the same direction is:

   1. 30N

   2. 40N

   3. 70N

   4. 10N

10. The magnitude of dot and cross product of two vectors are equal when angle between them is:

    1. Zero

    2. 45^o

    3. 90^o

    4. 270^o