Advertisements
Advertisements
प्रश्न
A transformer has 400 turns in the primary winding and 10 turns in the secondary winding. The primary e.m.f. is 250 V and the primary current is 2.0 A. calculate:
(a) The secondary voltage,
(b) The secondary current, assuming 100% efficiency.
Advertisements
उत्तर
Since, the number of turns in the primary is more than the no. of turns in the secondary it is a step-down transformer.
Given, NP= 400, Ns = 10, EP=250 V, IP= 2A
(a) Let Es be the secondary voltage.
We know that for transformer turn ratio `"N"_"s"/"N"_"p" = "I"_"p"/"I"_"s" = "E"_"s"/"E"_"P"`
Es = `"N"_"s"/"N"_"P" xx "E"_"P" = 10/400 xx 250 = 6.25 "V"`
(b) Let Is be the current though secondary
We know that for transformer turn ratio `"N"_"s"/"N"_"P" = "I"_"P"/"I"_"s"`
Is = `400/10 xx 2= 80 "A"`
APPEARS IN
संबंधित प्रश्न
State three differences between direct current and alternating current.
Prove theoretically (electromagnetic induction) `e = (dphi)/(dt)`
A circular coil of cross-sectional area 200 cm2 and 20 turns is rotated about the vertical diameter with angular speed of 50 rad s−1 in a uniform magnetic field of magnitude 3.0 × 10−2T. Calculate the maximum value of the current in the coil.
The coil of a moving-coil galvanometer keeps on oscillating for a long time if it is deflected and released. If the ends of the coil are connected together, the oscillation stops at once. Explain.
A conducting square loop having edges of length 2.0 cm is rotated through 180° about a diagonal in 0.20 s. A magnetic field B exists in the region which is perpendicular to the loop in its initial position. If the average induced emf during the rotation is 20 mV, find the magnitude of the magnetic field.
A coil has a self-inductance of 0·05 Henry. Find the magnitude of the emf induced in it when the current flowing through it is changing at the rate of 100 As-1.
Give an illustration of determining direction of induced current by using Lenz’s law.
The working of a dynamo is based on the principle of
In the current carrying conductor (AOCDEFG) as shown, the magnetic induction at point O is ______.
(R1 and R2 are radii of CD and EF respectively. l = current in the loop, μ0 = permeability of free space)
