Physics paper

Q.1:- The length of a wire is  when the tension in it is. The original length of the wire is

(a)                                (b)                              (c)                           (d)

Q.2:- A gaseous mixture consists of 16 g of helium & 16 g of oxygen. The ratio  of the mixture

is

(a)  1.4                                    (b)  1.54                                    (c)   1.59                                   (d)  1.62

Q.3:- A body cools from 60 to 50 in 10 min. If room temperature is 25, temperature of body at

the end of next 10 minute will be

(a)  38.5                                 (b)   40                           (c)  45                                   (d)  42.85

Q.4:- The earth rotates about the sun (see Fig.) in an elliptical orbit. At which point is velocity will be

maximum ?

A                                                   C

D DD

 

(a)  At  A                               (b)  At  B                                (c) At  C                                   (d)  At  D

Q.5:- When a system is taken from state 𝖎 to state f along a path   𝖎af, it is taken found that Q = 50

cal & W = 20 cal. Along  the path  𝖎bf Q = 36 cal. W along the path  𝖎bf is

a                                     f

 

𝖎                                     b

(a)  14 cal                               (b)  6 cal                                   (c)  16 cal                                    (d)   66 cal

Q.6:- Work done in taking a mass from one point to another in a gravitational field depends on

(a)  the end points only

(b)  the path followed

(c)  the velocity of the mass

(d)  both the length of the path & the end points.

Q.7:-  A particle is describing uniform circular motion. Its acceleration is

(a) along  the radius of circular path pointing  towards the centre

(b)  along  the tangent to the circular path

(c)  along  the radius of  the circular path pointing  away from  the centre

(d)  zero

Q.8:-   are the moments of inertia of two circular discs about their central axes perpendicular                                                                                                                                                      to their surfaces. Their angular frequencies of rotation are    respectively. If they are brought in contact face to face with their axes of rotation coinciding with each other, the angular frequency of the composition disc will be

(a)                                (b)                              (c)                       (d)

Q.9:-  The maximum range of a projectile is 100 m. The maximum height reached by it is

(a)   100 m                              (b)   25 m                               (c)  200 m                                    (d)  75 m

Q.10:- A  Carnot’s engine working between 27 & 127 has a work output of 200 J per cycle.          the   energy supplied to the engine from the source in each cycle is

(a)   400 J                              (b)  800 J                                (c)  600 J                                    (d)   500 J

Q.11:-  A particle is executing linear  simple  harmonic  motion. The fraction of the total energy that

is  potential, when  its  displacement is   of its amplitude  is

(a)                                 (b)                                   (c)                                      (d)

Q.12:-  The  third  overtone  of  an  open  organ pipe  is in  resonance with the second  overtone  of a

closed organ pipe. If  the length of the open  pipe is 8 cm, then the length of the closed pipe is

(a)   10  cm                              (b)  8  cm                                (c)  12  cm                                 (d)  5  cm

Q.13:-  The  correct  vector relation  between linear velocity   & angular velocity  in rigid body

dynamics   is  (is  the position vector)

(a)                      (b)                        (c)                   (d)

Q.14:- Magnitudes of four pairs of displacement vectors are given. Which pair of displacement    vectors, under vector addition, fails to give a resultant vector of magnitude  3 cm?

(a)   2 cm, 7 cm                        (b)  1 cm, 4 cm                  (c)  2 cm, 3 cm              (d)  2 cm , 4 cm

Q.15:- Water flows through  a pipe of varying cross section. Then the ratio of speeds of water at two

point 1 & 2 where the radii of the pipe are  is

(a)                                (b)                               (c)                                     (d)

Q.16:-  The satellite moving round the earth in a circular orbit of radius r & speed v suddenly loses of its energy. The

(a)  r will increase & v will decrease

(b)  both r & v will decrease

(c)  both   r  &  v will decrease

(d) r will decrease & v will increase

Q.17:- A body is projected up from the  surface of the earth with a velocity equal to   of its    escape  velocity. If  R be the radius  of earth, the height it reaches is

(a)                                                                           (b)

(c)                                                                           (d)

Q.18:-  The stress required to double the length of a wire of Young’s modulus Y  is

(a)                               (b)  2Y                            (c)  Y                                   (d)  4Y.

Q.19:-  A piece of ice, with a stone embedded inside it, is floating in water  contained in a vessel. When the ice melts completely, the level of water in the vessel

(a)   remains unchanged

(b)  rises

(c)   falls

(d) falls in the beginning  &  rises to the same level later.

Q.20:-  Radius of an air bubble at the bottom of the lake is r & it become 2r, when the air bubble rises to the top surface of the lake. If P cm of water be the atmospheric pressure, the  the depth of the lake is

(a)  2P                              (b)  8P                               (c)  4P                                (d)  7P

Q.21:-   If the force acting on a body is inversely proportional to its speed, then its kinetic energy is

(a) linearly related to time

(b)  inversely   proportional to time

(c)   inversely   proportional to the square  of  time

(d)  a constant.

Q.22:- A cricket ball of mass 0.5 kg strikes a cricket bat normally with a velocity of 20 m &       rebounds with a velocity of 10 m. The impulse of the force exerted by the ball on the bat is

(a)  15 Ns                             (b) 25 Ns                            (c) 30 Ns                           (d) 10  Ns.

Q.23:- The working principle of rocket propulsion is conservation of

(a)   angular momentum                                       (b)  mass

(c)    linear momentum                                          (d)  kinetic energy.

Q.24:- A body, possessing kinetic energy T, moving on a rough horizontal surface, is stopped in a

distance   y. The frictional force exerted on the body is

(a)  Ty                             (b)                                 (c)                                 (d)

Q.25:- Assuming earth to be an inertial frame, an example for inertial frame observer is

(a)  a driver in a train which is slowing down to stop

(b)  a person in a car moving with uniform velocity

(c)  a girl revolving in a merry-go round

(d)  a passenger in an aircraft which is taking off.

Q.26:- In   inelastic  collision,

(a)  momentum, kinetic energy & total energy are conserved.

(b)  momentum, kinetic energy & total energy are not conserved.

(c)  momentum & kinetic energy  are conserved  but  total energy are not conserved.

(d)  total energy  & momentum are conserved but kinetic energy is not conserved.

Q.27:- When the temperature of a gas is increased

(a)  its molecular kinetic energy increase

(b)  molecular potential energy decreases & molecular kinetic energy also decreases ; total

energy remaining constant

(c)   molecular potential  energy   increases & molecular kinetic energy also decreases ; total

energy remaining constant

(d)  its  molecular potential energy decreases.

Q.28:- The requirement for heat conduction to take place in solid is

(a)  density gradient

(b)  uniform density

(c)   temperature gradient

(d)   uniform  temperature

Q.29:- A  certain quantity of heat energy is given to a diatomic ideal gas which expands at constant

pressure. The  fraction  of the heat energy is converted into work is

(a)                               (b)                                 (c)                                 (d)

Q.30:- The excess pressure inside a cylindrical drop of liquid or a cylindrical bubble of radius R in a

(a)                              (b)                                 (c)                                 (d)

Q.31:- Two small spheres of radii r & 4r fall through a viscous liquid with the same terminal velocity.

The ratio between the viscous forces acting on them is

(a) 1 : 2                              (b) 4 : 1                            (c)   1 : 16                          (d) 1 : 4

Q.32:- A sound wave with frequency 256 Hz falls normally on a perfectly reflecting wall. The shortest

distance from the wall at which the air particles will have maximum amplitude of vibrations is

nearly (velocity of sound in air is 336 m/s )

• 8 cm (b) 50 cm                             (c) 65.6 cm                          (d) 25 cm