# JEE NEET PHYSICS MCQs (Set-4)

Topics Covered: Vector Algebra, Motion in a Plane

Q1: If θ is the angle between two vectors, then the resultant vector is maximum when the value of θ is

(a) 0°
(b) 90°
(c) 180°
(d) Same in all cases.

Q2: The change in a vector may occur due to

(a) Rotation of the frame of reference
(b) Translation of frame of reference
(c) Rotation of vector
(d) Both a and b

Q3: Acceleration of a particle under projectile motion at the highest point of its trajectory is :

(a) g
(b) zero
(c) less than g
(d) dependent upon projection velocity

Q4: The resultant of two vectors at an angle 150° is 10 units and is perpendicular to one vector. The magnitude of the smaller vector is

(a) 10 units
(b) 10√3 units
(c) 10√2 units
(d) 5√3 units

Q5: A particle is projected up the inclined such that its component of velocity along the incline is 10 m/s. Time of flight is 2 sec and a maximum height above the incline is 5 m. Then the velocity of projection will be:

(a) 10 m/s
(b) 10√2 m/s
(c) 5√5 m/s
(d) none of these

Q6: A particle is projected from the ground with speed 80 m/s at an angle 30° with horizontal from the ground. The magnitude of average velocity of particle in time interval t = 2 s to t = 6 s is [Take g = 10 m/s²]

(a) 40√2 m/s
(b) 40 m/s
(c) Zero
(d) 40√3 m/s

Q7: The velocity at the maximum height of a projectile is half its initial velocity (u).  Its range on the horizontal plane is:

(a) 2u²/3g
(b) u²√3/2g
(c) u²/3g
(d) u²/2g

Q8: The angle of projection, for which the horizontal range and the maximum height of a projectile are equal, is:

(a) 45°
(b) θ = tan⁻¹4
(c) θ = tan⁻¹ (0.25)
(d) none of these.

Q9: At the highest point on the trajectory of a projectile, its

(a) potential energy is minimum
(b) kinetic energy is maximum
(c) the total energy is maximum
(d) kinetic energy is minimum.

Q10: The range of a projectile is R when the angle of projection is 40°. For the same velocity of projection and range, the other possible angle of projection is:

(a) 45°
(b) 50°
(c) 60°
(d) 40°

1: (a) 0°

2: (c) Rotation of vector

3: (a) g  [Note: g is constant near the surface of the earth.]

4: (b) 10√3 units

5: (b) 10√2 m/s

6: (d) 40√3 m/s

7: (b) u²√3/2g

8: (b) θ = tan⁻¹4

9: (d) kinetic energy is minimum.
[Note: Velocity and kinetic energy are minimum at the highest point.]

10: (b) 50° [Note: Range is same for the angle of projection θ and (90° – θ)]  