11.

A thin conducting ring and radius R is given charge +Q. The electric field at the centre O of the ring due to the charge on the part AKB of the ring is E. The electric field at the centre due to the charge on the part ACDB of the ring is 

• 3E along KO

• E along OK

• E along KO

• E along KO

A particle moves in a straight line with a constant acceleration. It changes its velocity from 10 ms^-1 to 20 ms^-1 while passing through a distance 135 m in t second.  The value of t is 

• 10

• 1.8

• 12

• 12

A thin rod of length L and Mass M is bent at its midpoint into two halves so that the angle between them is 90^o. The moment of inertia of the bent rod about an axis passing through the bending point and perpendicular to the plane defined by the two halves of the rod is 

• ML²/24

• ML²/12

• ML²/6

• ML²/6

A particle of mass is projected with the velocity v making an angle of 45^o with the horizontal. 
When the particle  lands on the level ground the magnitude of the change in its momentum will be

• 2 mv

• 
• 
• 

Sand is being dropped on a conveyor belt at the rate of M kg/s. The force necessary to keep the belt moving with a constant velocity of v m/s will be

• Mv newton

• 2 Mv newton

• Mv/2 Newton

• Mv/2 Newton

Which two of the following five physical parameters have the same dimensions?

1) Energy density
2) refractive index
3) dielectric constant
4) Young's modulus
5) Magnetic field

• 2 and 4

• 3 and 5

• 1 and 4

• 1 and 4

On a new scale of temperature (which is linear), an called the W scale, the freezing and boiling point of water are 39^o W and 239^o W respectively. what will be the temperature of 39^o C  celsius scale?

• 78^o W

• 117^o C

• 200^o C

• 200^o C

If Q, E andW denote respectively the heat added, change in internal energy and the work done in a closed cycle process, then

• W =0

• Q = W = 0

• E=0

• E=0

Two simple harmonic motions of angular frequency 100 and 1000 rad s^-1 have the same displacement amplitude. The ratio of their maximum acceleration is 

• 1:10

• 1:10²

• 1:10³

• 1:10³

An electric kettle takes 4 A current at 220 V. How much time will it take to boil 1 kg of water from temperature 20⁰ C? The temperature boiling water is 100^o C^.

• 6.3 min

• 8.4 min

• 12.6 min

• 12.6 min