VITEEE 2016 :: Physics :: General questions

• Physics - General questions

 In given circuit , all resistance are of 10 Ω current flowing through ammeter is 

.

Answer:

Explanation:

 An equivalent of the given network is as shown in figure.

 If R_p be the net resistance, then

$\frac{1}{R_{p}}=\frac{1}{10}+\left(\frac{1}{10+10}\right)+\left(\frac{1}{10+10}\right)+\frac{1}{10}$

$=\frac{1}{10}+\frac{1}{20}+\frac{1}{20}+\frac{1}{10}=\frac{6}{20}=\frac{3}{10}$

$\therefore$    $R_{p}=\frac{10}{3}$Ω

 Hence, current f;owing  through ammeter is 

  $I=\frac{V}{R_{p}}=\frac{12}{(\frac{10}{3})}=3.6 A$

 Hologram is based on phenomenon of

Answer:

Explanation:

Hologram is based on the phenomenon of interference

 A square current-carrying loop is changed to a circular loop in time t₁. Then

Answer:

Explanation:

For the time t < t₁ , area of loop changes Hence, magnetic flux linked with it changes during this time and emf induced thereby

 For a current-carrying inductor, emf associated is 20m V. Now, the current through it changes from  6A to 2A in 2 s. The coefficient of mutual  inductance is 

Answer:

Explanation:

$|e|=L\frac{dI}{dt}$

 Here, e= 20mV= 20x 10^-3 V

 $\frac{dI}{dt}=\frac{6-2}{2}=2A/s$

  L= ?

 $\Rightarrow  20\times 10^{-3}=L \times 2$

 $\therefore$     L= 10x 10^-3= 10mH

 In shown fig. the circular loop of wire is moved with velocity  towards the infinite current-carrying wire, then

Answer:

Explanation:

The magnetic field at the centre of the circular loop increases as it moves towards the current-carrying wire as we know it varies inversely with the distance. Therefore, the induced current in the loop should be such that it can reduce the increased magnetic field. This is possible only when the induced current is clockwise

• Physics - General questions