Physics MCQs for NEET — Practice Questions with Answers

When a ball is thrown vertically upwards, its velocity decreases as it ascends due to the force of gravity acting in the opposite direction. At the peak of its ascent, the velocity becomes zero. As the ball starts descending, gravity causes its velocity to increase in the downward direction. Therefore, the velocity of the ball decreases when it is going up. Hence, the correct option is o2.

$$ V_1 + V_2 = 5 $$ $$ V_1 -V_2 = 1 So 2V_1 = 6 $$ $$ V_1 = 3 m/s $$

$ V = ( A + y ) ^{1 /2 } $ $ \therefore a = { dv \over dt } = { dv \over dy } . { dy \over dt } $

$ s = { v^2 \over 2 a } $

For a train moving with constant acceleration, the speed of the last wagon can be found using the kinematic equations. Given that the speed of the engine when it passes the signal is U and the speed at the midpoint is V, we can use the relationship between these speeds to find the speed of the last wagon. The correct formula is $ ext{speed} = \\sqrt{2V^2 - U^2} $, which matches option o4.

The area under an acceleration vs. time graph represents the change in velocity over a given time interval. This is derived from the definition of acceleration, which is the rate of change of velocity. Therefore, integrating acceleration with respect to time gives the change in velocity. Hence, option o3 is correct.

For perfectly reflecting surface, momentum transferred = 

The equations given for displacement are x = 3sin(2t) and y = 3cos(2t). These represent parametric equations of a circle with radius 3. The speed of a particle moving in a circle with constant radius and angular speed is constant. Thus, the speed is constant and non-zero. Hence, option o2 is correct.

A vector quantity is defined by having both a magnitude and a direction. For example, velocity is a vector because it specifies how fast something is moving (magnitude) and in which direction. Therefore, to introduce a vector quantity, it needs both magnitude and direction.

Electric current is a scalar quantity. Unlike vectors, scalar quantities have only magnitude and no direction. Electric current is described by its magnitude, which is the rate of flow of charge through a conductor, but it does not have a specific direction in the sense that a vector does.