A small uncharged metallic sphere is positioned exactly at a point midway between two equal and opposite point charges. If the sphere is slightly displaced towards the positive charge and released then
 

1.  it will oscillate about its original position
2.  it will move further towards the positive charge
3.  its electric potential energy will decrease and kinetic energy will increase
4.  its total energy remains constant but is non-zero

Subtopic:  Electric Potential Energy |
Please attempt this question first.
Hints

A capacitor of capacitance 5μF is connected as shown in the figure. The internal resistance of the cell is 0.5 Ω. The amount of charge on the capacitor plate is 
1.  zero
2.  5μC
3.  10μC
4.  25 μC

 

Subtopic:  Capacitance |
Please attempt this question first.
Hints

The resistance if a circular coil of 50 turns and 10 cm diameter is 5Ω. What must be the potential difference across that ends of the coil so as to nullify the earth’s magnetic field (H=0.314 gauss) at the centre of the coil? How should the coil be placed to achieve this result?
 

1.  0.5 V with plane of coil normal to the magnetic meridian
2.  0.5 V with plane of coil in the magnetic meridian
3.  0.25 V with plane of coil normal to the magnetic meridian
4.  0.25 V with plane of coil in the magnetic meridian

Subtopic:  Earth's Magnetism (OLD NCERT) |
Please attempt this question first.
Hints

advertisementadvertisement

A body of mass 0.5 kg is projected under gravity with a speed of 98 m/s at an angle of 60 ° with the horizontal. The change in momentum (in magnitude) of the body is
 
1.  24.5 N-s
2.  49.0 N-s
3.  98.0 N-s
4.  50.0 N-s

 

Subtopic:  Projectile Motion |
Please attempt this question first.
Hints

advertisementadvertisement

The dispersive powers of glasses of lenses used in an achromatic pair are in the ratio 5 : 3. If the focal length of the concave lens is 15 cm, then the nature and focal length of the other lend would be
 
1.  convex, 9 cm
2.  concave, 9 cm
3.  convex, 25 cm
4.  concave, 25 cm

 

Subtopic:  Lenses |
Please attempt this question first.
Hints

A charge Q is divided into two parts of q and Q-q. If the coulomb repulsion between them when they are separated is to be maximum, the ratio of  should be
 
1.  2
2.  1/2
3.  4
4.  1/4

 

Subtopic:  Coulomb's Law |
Please attempt this question first.
Hints

advertisementadvertisement

 
A rectangle vessel when full of water, takes 10 mint to be emptied through an orifice in its bottom. How much time will it take to be emptied when half filled with water?
 
 
1.  9 min
2.  7 min
3.  5 min
4.  3 min

 

Subtopic:  Bernoulli's Theorem |
 55%
Please attempt this question first.
Hints