The Ratio Of The Number Of Turn In The Primary And The Secondary Coil Of A Step-up Transformer Is 1 : 200. It Is Connected To A-C Mains Of 200 V. Calculate The Voltage Developed In The Secondary. Determine The Current In The Secondary, When A Current Of 2.0 A Flows Through The Primary.   

Why Kaysons ?

Video lectures

Access over 500+ hours of video lectures 24*7, covering complete syllabus for JEE preparation.

Online Support

Practice over 30000+ questions starting from basic level to JEE advance level.

Live Doubt Clearing Session

Ask your doubts live everyday Join our live doubt clearing session conducted by our experts.

National Mock Tests

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

Organized Learning

Proper planning to complete syllabus is the key to get a decent rank in JEE.

Test Series/Daily assignments

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.



The ratio of the number of turn in the primary and the secondary coil of a step-up transformer is 1 : 200. It is connected to A-C mains of 200 V. Calculate the voltage developed in the secondary. Determine the current in the secondary, when a current of 2.0 A flows through the primary.   


Correct option is

40,000 V, 0.01 A

If Np and Ns be the number of turns in the primary and the secondary coils respectively, and Vp and Vs be the primary and the voltages, then we have  


Suppose, the currents through the primary and the secondary are ip and isrespectively. Then, assuming that the transformer is ‘ideal’, we have  






In a series L-C-R circuit connected to a variable frequency 220-V source; we have : L = 4.0 H, . Calculate the resonant frequency of the circuit.   


A variable-frequency 230-V alternating voltage source is connected across a series combination of L = 5.0 H,  and . Calculate the angular frequency of the source which drives the circuit in resonance. 


A series LCR circuit with L = 0.12 H, C = 480 nF and  is connected to a 230-V variable-frequency supply. What is the source frequency for which current a amplitude is maximum? Find this maximum value.


An L C R circuit has L = 10 mH connected in series to a source of  volt. Calculate the current-amplitude and the average power dissipated per cycle at a frequency 10% lower than the resonant frequency. 


A 750-Hz, 20-V source is connected to a resistance of , an inductance of 0.1803 H and a capacitance of , all in series. Calculate the time in which the resistance (thermal capacity = 2 JoC–1) will get heated by 10oC. 


Obtain the resonant frequency and Q-factor of a series LCR circuit with L= 3.0 H. How will you improve the sharpness of resonance of the circuit by reducing its full width at half maximum by a factor of 2?  


A virtual current of 4 A flows in a coil when it is connected in a circuit having a.c. of frequency 50 Hz. The power consumed in the coil is 240 W. Calculate the inductance of the coil if the virtual p.d. across it is 100 V. 


An a.c. circuit having an inductor and a resistor in series draws a power of 560 W from an a.c. source marked 210 V-60 Hz. The power factor of the circuit is 0.8. Calculate the impedance of the circuit and the inductance of the inductor. 


A town situated 20 km away from a power plant generating power at 440 V, requires 600 kW of electric power at 200 V. The resistance of the two-wire line carrying power is  /km. The town gets power from the line through a 3000-220 V step-down transformer at a sub-station in the town. Estimate the line power loss as heat.  


Calculate the current drawn by the primary of a transformer which steps down 200 V to 20 V to operate a device of resistance . Assume the efficiency of transformer to be 80%.