R.S.K HIGHER SECONDARY SCHOOL,TRICHY.
Managed by: DAV group of schools, Chennai.
SUBJECT ENHANCEMENT TEST-1
Std :XI Marks:25
Subject: physics Time: 40Mins
Date:21/10/22
Section - A
1. A person sitting in the compartment of a train moving with uniform speed throws a ball in the
upward direction. What path of the ball will appear to him? What to a person standing outside the
train? (1)
2. Why does the electric fan continue to rotate for some time after the current is switched off? (1)
3. A gun of mass 1000 kg fires a projectile of mass 1 kg with a horizontal velocity of 100 m/s. The
velocity of recoil of the gun in the horizontal direction is (1)
(a) 5 m/s (b) 0.1 m/s (c) 15 m/s (d) 20 m/s
4. A bullet of mass 25 g moving with a velocity of 200 cm/s is stopped within 5 cm of the target. The
average resistance offered by the target is (1)
(a) 1 N (b) 2 N (c) 3 N (d) 4 N
5. In an explosion, a body breaks up into two pieces of unequal masses. In this (1)
(a) both parts will have numerically equal momentum
(b) lighter part will have more momentum
(c) heavier part will have more momentum
(d) both parts will have equal kinetic energy
Assertion and Reason : (3X1=3)
Directions : Each of these questions contain two statements, Assertion and Reason. Each of these
questions also has four alternative choices, only one of which is the correct answer. You have to select
one of the codes (a), (b), (c) and (d) given below.
(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion.
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct.
6. Assertion: A cricketer moves his hands forward to catch a ball so as to catch it easily without
hurting.
Reason: He tries to decrease the distance travelled by the ball so that it hurts less.
7. Assertion : A block placed on a table is at rest, because action force cancels the reaction force on
the block.
Reason : The net force on the block is zero.
8. Assertion : An object can move with constant velocity if no net force acts on it.
Reason : No net force is needed to move an object with constant velocity.
Section - B
9. A body of mass m moves along X- axis such that its position co-ordinate at any instant t is
x= at4-bt3+ct, where a ,b and c are constants. What is the force acting the particle at any instant t?(2)
Or
A body of mass 5kg is acted upon by two perpendicular forces of 8N and 6N.Give the magnitude and
direction of the acceleration of the body. (2)
10. It is easier to roll a barrel than to pull it along the road. why? (2)
11. A person is standing on ice at a place A in a freezed pond. He has a pistol and two bullets. How
can he move from the place A to another distance place B, and stop there? (2)
Section - C
12. A boy pulls a toy having two carriages placed on a frictionless table by applying a force of 1.5 N at
30°in a vertical plane . Calculate (i)the acceleration of the 40g carriage. (ii)the acceleration of the 20g
carriage and (iii) the tension in the string fastened between the two carriage. (3)
Or
In the figure ahead ,three blocks are connected by strings. Masses of blocks are m,3m and 5m
respectively and they are pulled by a force T3 on a frictionless horizontal surface. The tension T1 in the
first string is 16N.Calculate (i)acceleration of blocks ,(ii)tension T2in the second string,(iii) Force T3.
13. A person of mass m is standing in a lift. Find his apparent weight when the lift is ;(i) moving
upward with uniform acceleration ‘a’. (ii) moving downward with uniform acceleration ‘a’.(iii)moving
with constant velocity.(iv) falls freely. (3)
Section - D
14.(a)Derive the law of conservation of linear momentum from Newton’s second law of motion.
(b)Two masses M and m are connected at the two ends of an inextensible string. The string passes
over a smooth frictionless pulley. Calculate the acceleration of the masses and the tension in the string.
Given M > m. (3+2=5)
Or
(a)When a horse pulls a cart , according to Newton’s third law ,the cart also pulls the horse with an
equal and opposite force .What causes the motion of the horse ,cart and the system as a whole?
Explain with a diagram.
(b) A shell of mass 0.02 kg is fired by a gun of mass 100kg.The muzzle speed of the shell is 80ms-
1
.Find the recoil speed of the gun. (3+2=5)
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