Question 1 :
A transformer steps up an $AC$supply from$220 V$to$2200V$. If the secondary coil of the transformer has$2000$turns, the number of turns in its primary coil will be:
Question 2 :
The number of turns in primary and secondary coils of a transformer is 50 and 200 respectively. If the current in the primary coil is 4A, then the current in the secondary coil is :<br/>
Question 3 :
A transformer having $4000$ turns on its primary side and $500$ turns on the secondary side. If the input voltage is $240\ V$, find out the output voltage of the secondary side of the transformer ?
Question 4 :
A step-down transformer reduces the voltage of a transmission line from $2200\ V$ to $220\ V$. The power delivered by it is $880\ W$ and its efficiency is $88$%. The input current is :
Question 5 :
A step up transformer operates on a $230V$ line and supplies to a load $2A$. The ratio of primary to secondary windings is $1:25$. Determine the primary current.
Question 6 :
In a primary coil $5 A$current is flowing on$220$volts. If thesecondary coil produces$2200V$voltage. Then the ratioof number of turns insecondary coil and primary coil will be
Question 7 :
A transformer is used to light a $120 W$,$24 V$lamp from$240 V$a.c. mains. The current in the main cableis$0.6 A$.The efficiency of the transformer is
Question 8 :
A step up transformer converts $100$ V at primary to $300$ V at secondary.  If the primary current is $6$A, then the secondary current is ______A
Question 9 :
In a transformer the output current and voltage are $4 A$and$20 V$respectively. If the ratio of number ofturns inthe primary and secondary coil is$2 : 1$respectively, what isthe input current and voltage?
Question 10 :
An ideal transformer has 500 and 5000 turns inprimary and secondary winding respectively. If theprimary coil is connected to a 6 V battery then thesecondary voltage is :
Question 11 :
In a transformer, the number of turns of primary coiland secondary coil are 5 and 4 respectively. If 220V is applied on the primary coil, then the ratio ofprimary current to the secondary current is :
Question 15 :
Match the following<br/>a) step up transformer     d) turns ratio is 1<br/>b) step down transformer e) Ns > Np<br/>c) Ideal transformer           f) Np > Ns<br/>
Question 16 :
If a stepup transformer develops 400V in secondary coil for an input of 200V A.C, then the current in the transformer is :<br/>
Question 17 :
A device that increases the voltage of an alternating current is called a(n)
Question 19 :
A step-up transformer of turns ratio $2 : 1$has$50 Hz$ <br> $AC$voltage applied to primary. The frequencyof$AC$output voltage across secondary is
Question 21 :
<p>Turn ratio in a setup transformer is 1: 2.If a lechlanche cell of 1.5 V is connected across the input, what is the voltage across the output?</p>
Question 22 :
Assertion: A step up transformer can also be used as a step down transformer.
Reason: This is because $\cfrac { { E }_{ p } }{ { E }_{ s } } =\cfrac { { n }_{ s } }{ { n }_{ p } } $
Question 24 :
In a step-down transformer the secondary coil has .............. number of turns.<br><br>
Question 25 :
An ideal transformer has 400 turns in the primary and 200 turns in the secondary. If the primary is connected to a 12 V battery, then the secondary voltage is<br/>
Question 26 :
A transformer with a $110 V$ primary has a $15:1$ turns ratio. The load resistance, $R_L$, is $120$ . What is the approximate voltage across the load?<br/>
Question 27 :
The ratio of the secondary to the primary turns in a transformer is $3:2$ and the output power is $P$. Neglecting all power losses, the input power must be:<span class="_wysihtml5-temp">
Question 28 :
The primary of a transformer has $400$ turns while the secondary has $2000$ turns. If the power output from the secondary at $1000V$ is $12kW$, what is the primary voltage?
Question 29 :
The primary and secondary coils of a transformer<br>have 50 and 1500 turns respectively. If the<br>magnetic flux linked with the primary coil is<br>given by $\phi =\phi _{0}+4t,$ where $\phi$ is in webers, t is<br>time in seconds and $\phi_{0}$ is a constant, the output<br>voltage across the secondary coil is:<br><br><br><br><br><br>
Question 30 :
A transformer connected to $220$ volt line shows an output of $2A$ at $11000V$. The efficiency is $100$%. The current drawn from the line is: