Thursday, September 15, 2011

Electricity and Magnetism - TRB Physics Study Materials


SI NO.
QUESTIONS
ANSWERS
1.        
The conducting power of magnetic lines of force as compared to air is called?
Permeability
2.        
The retaining power of magnetism  is more in?
Steel
3.        
Paramagnetic substances are?
Platinum
4.        
Susceptibility of paramagnetic material is?
Small positive
5.        
When a diamagnetic material is suspended it sets itself?
Right angles to the field
6.        
The residual intensity of magnetization left in the specimen when the magnetizing field is switched off is called?
Retentivity
7.        
The susceptibility of a diamagnetic material has a ?
Low negative value
8.        
The unit of intensity of magnetization is ?
Amp-turns/metre
9.        
Iron, cobalt, nickel and their alloys are?
Ferro magnetic
10.    
The silicon-iron is called?
Transformer steel
11.    
All charges in nature occur an integral multiple of?
Q=ne
12.    
Bodies which allow the charge to pass through them are?
Conductors
13.    
Force between two point charges is directly proportional to the product of charges and inversely proportional to square of the distance between them, this is?
Coulomb’s law
14.    
The value of relative permittivity for air is equal to?
1
15.    
Electric field E?
F/q and v/d
16.    
The lines of forces are?
Never intersect
17.    
Two opposite charges separates by a small distance is called?
Dipole
   18.
Electric flux due to a charge outside the closed surface is?
zero
   19.
The unit of capacitance of?
Farad
   20
Electric flux through curved surface is?
E ds cos
   21
Capacitance is equal to?
qv
22
A capacitor is a device for storing?
Electric current
23
An insulating material in which all the electrons are tightly bound to the nucleus of the atom is called?
Dielectrics
   24
Molecular Polaris ability is?
P/E
25
The rms value of an a.c is equal to?
0.707 times peak value of the a.c and 70.7% of a.c peak value