0.0000267Ωcm
0.006Ωcm
0.26700Ωcm
0.27500Ωcm
0.060000Ωcm
Correct answer is B
R = αL/A
P = RA/L = (3 x 0.004)/2 = 0.006
Which of the following statement is not correct about loaded spiral spring?
The extension is proportional to the load applied, provided the elastic limite is not exceeded
If the elsatic limit is not exceeded, the contraction is proportional to the load removed.
Up to the yield limit, extension is no longer proportional to the applied load.
Beyond the elsatic limit, extension is no longer proportional to the applied load.
If the string regains its shape or form after deformation, it is said to be elastic.
Correct answer is C
No explanation has been provided for this answer.
What is the effect of using split-rings in a simple d.c motor?
The direction of rotation of the coil is reversed
The current in the coil flows in the same direction
The current in the coil becomes alternating
The direction of the force on the coil is reversed
The contact with the voltage is cut-off
Correct answer is A
Split ring is used for reversing the direction of current in the coil. For the continuous rotation of the coil in the same direction, the current in the coil must be reversed.
216000J
13200J
3600J
864J
220J
Correct answer is A
E = pt
=> 60 x 1 x 60 x 60 = 216000J
64 minutes
32 minutes
8 minutes
2 minutes
1 minute
Correct answer is E
D ∝ l2
E will increase 4 times when current is doubled.
Therefore time will decrease by a factor of 4, which is 1 minute.