Magnetic lines of force
form closed circuits
cannot intersect
are crowded together near the poles
all the above are correct
At what voltage is the electric power generated at the power generating station?
11 kV
25 kV
21 kV
40 kV
A fuse is used in mains electric supply as a safety device. Which one of the following statements about the fuse is correct?
It is connected in parallel with the main switch.
It is made mainly from silver alloys.
It must have a low melting point.
It must have a very high resistance
The north-south polarities of an electromagnet can be found easily by using :
Fleming's right-hand rule
Fleming's left-hand rule
Clock face rule
Left-hand thumb rule
The unit of self inductance is
henry
weber/m2
siemens
ampere-turn per weber
The electric appliances in a house are connected in
series
parallel
either series or parallel
both in series and parallel
Fuse wire is generally made of alloy of
Tin and lead
Nichrome
Lithium
Copper
are mere directions
have no physical reality
can be used to indicate the direction of the magnetic of the magnetic field of a point
A fuse wire is always connected to:
Earth wire
Neutral wire
Live wire
Between live and neutral lines
The magnetic field lines :
intersect at right angles to one another
intersect at an angle of 45o to each other
do not cross one another
cross at an angle of 60o to one another
