What is immaterial for an electric fuse wire?
Its specific resistance
Its radius
Its length
Current flowing through it
When there is an electric current through a conducting wire along its length then an electric field must exist ____.
inside the wire but normal to it
inside the wire but parallel to it
outside the wire but normal to it
outside the wire but parallel to it
Two identical heater coils are connected in parallel across the mains. If one of the coils breaks, then other coil ____.
will also not be heated
develop a higher temperature
develop a lower temperature
will develop the same amount
When 1 gm hydrogen 9 e.c.e. = 1.044 x 10-8 kg/coul) from water, 34 Kcal heat is liberated. The minimum voltage required to decompose water is ____.
0.75 V
3.0 V
1.50V
4.5V
Which one of the following is a vector?
Electric potential
e.m.f
electrical energy
electrostatic force
Two electric bulbs rated for the same voltage have power of 200 watt and 100 watt. If their resistances are respectively R1 and R2 then ____.
R1 = 2R2
R2 = 2R1
R2 = 4R1
R1 = 4R2
The production of e.m.f. by maintaining a difference of temperature between the two junctions of two different metals is known as :
Joule effect
Seebeck effect
Peltier effect
Thomson effect
When a current passes through the junction of two different metals, evolution or absorption of heat at the junction is known as :
Joule effect
Seebeck effect
Peltier effect
Thomson effect
The true statement for thermo e.m.f. of a thermocouple :
Depends on the nature of metals
Depends only on temperature of cold junction
Depends only on temperature of hot junction
Depends on the length of the wires used for thermocouple
The direction of current in an iron-copper thermocouple is :
From copper to iron at the hot junction
From iron to copper at the hot junction
From copper to iron at cold junction
No current will flow