A boy standing on a moving truck throws a projectile such that he is able to catch it back after the truck has moved 100 m. if the truck is moving horizontally along a straight line with a constant speed 30 m/s, at what speed (relative to the truck) must the projectile is thrown.(Assume, g=10 m/s2)

A) $\frac{55}{3} m/s$

B) $\frac{43}{2} m/s$

C) $\frac{50}{3} m/s$

D) $\frac{23}{3} m/s$


An iron rod of length 1.5 m lying on a horizontal table is pulled up from one end along a vertical line so as to move it with a constant velocity 3 m/s. while the other end of the rod slides along the floor. After how much time the speed of the end sliding  on the floor equals to the speed of the end being pulled up

A) $\frac{1}{2\sqrt{2}}s$

B) $\frac{1}{\sqrt{2}}s$

C) $3\sqrt{2}$s

D) $\frac{1}{4}$


 A particle covers a distance from A to B over a period of time; the distance versus time plot is shown below. Then which of the following is true for the motion of the particle?


A) Both average speed and instantaneous speed are always zero

B) Average speed is always non-zero but instantaneous speed can be zero

C) Instantaneous speed is always non-zero but average speed can be zero

D) Both average speed and instantaneous speed are always non-zero


A current carrying conductor obeys Ohm's law  (V= RI). If the current passing through the conductor is  $l=(5\pm0.2)$A  and voltage   developed  is  $V=(60\pm6)$ V , then find the percentage  of error is resistance, R

A) 18

B) 6

C) 14

D) 2


Identify the correct option


A) The rang of the gravitonal force is large but not infinite

B) The range of electromagnetic force is large but lesser than the range of gravitational force

C) The range of weak nuclear force is smaller than the range of strong nuclear force, gravitation force and electromagnetic force

D) The range of the weak as well as strong nuclear force is of the the order of $10^{-10}$ m