NEET Sample Paper NEET Sample Test Paper-60

  • question_answer
     A circuit contains an ammeter, a battery of 30V and a resistance \[40.8\Omega \]all connected in series. If the ammeter has a coil of resistance \[480\Omega \] and a shunt of\[20\Omega \], the reading in the ammeter will be:

    A) 2A                   

    B) 1A    

    C) 0.5A                

    D) 0.25A

    Correct Answer: C

    Solution :

    [b] \[\frac{{{I}_{1}}}{{{I}_{2}}}=\alpha {{I}_{1}}=\alpha {{I}_{2}}\] \[{{I}_{\max }}={{\left( \sqrt{{{I}_{1}}}+\sqrt{{{I}_{2}}} \right)}^{2}}\] \[{{I}_{\max }}={{\left( \sqrt{\alpha {{I}_{2}}}+\sqrt{{{I}_{2}}} \right)}^{2}}=\alpha {{I}_{2}}+{{I}_{2}}+2\sqrt{\alpha }{{I}_{2}}\] \[{{I}_{\min }}={{\left( \sqrt{\alpha {{I}_{2}}}-\sqrt{{{I}_{2}}} \right)}^{2}}=\alpha {{I}_{2}}+{{I}_{2}}-2\sqrt{\alpha }{{I}_{2}}\] \[{{I}_{\max }}+{{I}_{\min }}=2\alpha {{I}_{1}}+2{{I}_{2}}=2{{I}_{2}}[1+\alpha ]\] \[{{I}_{\max }}-{{I}_{\min }}=4{{I}_{2}}\sqrt{\alpha }\] \[(1)\div (2)\] \[\frac{4{{I}_{2}}\sqrt{\alpha }}{2{{I}_{2}}[1+\alpha ]}=\frac{2\sqrt{\alpha }}{1+\alpha }\]


You need to login to perform this action.
You will be redirected in 3 sec spinner