00:01
So, in this question the given data is we have the value of voltage that is v which is equal to 220 volts.
00:09
We have the value of speed that is n1 which is equal to 800 rpm and we also have the current which is i1 which is given that is 100 ampere and we also have the resistance value that is r which is equal to 0 .10.
00:26
Now the value of new torque we also have the value of new torque.
00:33
New torque is the is half of the old torque.
00:44
So, basically this we have since we know that the t is that is torque is directly proportional to i square and for the t2 it is equal to half of t1 as it is given mentioned in the question that new torque we are considering new torque as t2 and old torque as t1.
01:04
So, therefore i2 square will be equal to half of i1 square which will be equal to half of i1 value is 100 which is square.
01:19
So, this will be equal to 5000.
01:21
Now we will take the roots i2 will be equal to root over 5000 which will be equal to 70 .7 ampere.
01:31
Now for the expression for emf e1 is given by e1 will be equal to v minus i1 r1.
01:38
So, we will put the value...