11.

The potential energy of a system increase if work is done

• By the system against a conservative force

• By the system against a nonconservative

• upon the system by a conservative force

• upon the system by a conservative force

A missile is fired at maximum range with an initial velocity of 20 m/s. If g =10 m/s² the range of the missile is 

• 50 m

• 60 m

• 20 m

• 20 m

Force F on a particle moving in a straight line varies with distance d as shown in the figure. The work done on the particle during its displacement of 12 m is

• 21 J

• 26 J 

• 13 J

• 13 J

Uniform magnetic field acting along AB. If the magnetic force on the arm BC Is F, the force on the arm AC is

• -F
• F
• 
• 

A body of mass M hits normally a rigid wall with velocity v and bounces back with the same velocity. The impulse experienced by the body is 

• 1.5 Mv

• 2 Mv

• zero

• zero

Two waves are represented by the equations, m where x is in metre and t in second. The phase difference between them is

• 1.25 rad

• 1.57 rad

• 0.57 rad

• 0.57 rad

Out of the following functions representing motion of a particle which represents SHM

• Only (IV) does not represent SHM

• (I) and (III)

• (I) and (II)

• (I) and (II)

Sound waves travel at 350 m/s through a warm air and at 3500 m/s through brass. The wavelength of a 700 Hz acoustic wave as it enters brass from warm air.

• increases by a factor 20

• increases by a factor 10

• decreases by a factor 20

• decreases by a factor 20

Light of two different frequencies whose photons have energies 1 eV and 2.5 eV respectively illuminate a metallic surface whose work function is 0.5 eV successively. Ratio of maximum speeds of emitted electrons will be

• 1:2

• 1:4

• 1:5

• 1:5

When 1 kg of ice at 0^oC  melts to water 0^oC, the resulting change in its entropy, taking latent heat of ice to be 80 cal/^oC, is

• 8 x 10⁴ cal /K

• 80 cal/K

• 293 cal/ K

• 293 cal/ K