Determine the height above the dashed line XX’ attained by the water stream coming out through the hole is situated at point B in the diagram given below. Given that h = 10 m, L = 2 m and d = 30 º 

1. 10 m

2. 7.5 m

3. 5 m

4. 3.2 m

If the magnetizing field on a ferromagnetic material is increased, its permeability

1. decreased

2. increased

3. is unaffected

4. may be increased or decreased

A ball is dropped from a bridge 122.5 m above a river. After the ball has been falling for 2s, a second ball is thrown straight down after it. What must the initial velocity of the second ball be so that both hit the water at the same time?

1. 40 m/s

2. 55.5 m/s

3. 26.1 m/s

4. 9.6 m/s

A body of mass 40 kg resting on rough horizontal surface is subjected to a force P which is just enough to start the motion of the body. If   and the force P is continuously applied on the body, then the acceleration of the body is

1. Zero

2. 1 $m/s^2$

3. 2 $m/s^2$

4. 2.4 $m/s^2$

The self inductance of a coil having 500 turns is 50 mH. The magnetic flux through the cross-sectional area of the coil while current through it is 8 mA is found to be

1. $4\times {10}^{-4} Wb$

2. $0.04 Wb$

3. $4\mu Wb$

4. 40 mWb

A uniform metallic rod rotates about its perpendicular bisector with constant angular speed. If it is heated uniformly to raise its temperature slightly, then

1. its speed of rotation increases

2. its speed of rotation decreases

3. its speed of rotation remains same

4. its speed increases because its moment inertia increases

A uniform disc is acted by two equal forces of magnitude R. One of them, acts tangentially to the disc, while other one is acting a the central point of the disc. The friction between disc surface and ground surface is nF. If r be the radius of the disc, then the value of n would be (in N)

1. 0

2. 1.2

3. 2.0

4. 3.2

While keeping area of cross-section of a solenoid same, the number of turns and length of solenoid one both doubled. The self inductance of the coil will be

1. halved

2. doubled

3. $\frac{1}{4}$ times the original value

4. unaffected 

Consider the circular loop having current I and with central point O. The magnetic field at the central point O is 
                                      

1. $\frac{2 {\mu }_0 i}{3 \mathrm{\pi } \mathrm{R}}$ acting downward

2. $\frac{5 {\mu }_0 i}{12 \mathrm{R}}$ acting downward

3. $\frac{6 {\mu }_0 i}{11 \mathrm{R}}$ acting downward

4. $\frac{3 {\mu }_0 i}{7 \mathrm{R}}$ acting downward