NEET 2010 PYQ Mock Test

A conducting circular loop is placed in a uniform magnetic field, $B=0.025\text{ T}$ with its plane perpendicular to the loop. The radius of the loop is made to shrink at a constant rate of $1{\text{ mms}}^{-1}$. The induced emf when the radius is $2\text{ cm}$ is:

In the given circuit the reading of voltmeter $V_1$ and $V_2$ are $300\text{ volts}$ each. The reading of the voltmeter $V_3$ and ammeter $A$ are respectively:

A $220\text{-volt}$ input is supplied to a transformer. The output circuit draws a current of $2.0\text{ ampere}$ at $440\text{ volts}$. If the efficiency of the transformer is $80\%$, the current drawn by the primary windings of the transformer is:

A source $S_1$ is producing $10^{15}\text{ photons per second}$ of wavelength $5000\text{ A˚}$. Another source $S_2$ is producing $1.02\times 10^{15}\text{ photons per second}$ of wavelength $5100\text{ A˚}$. Then (power of $S_2$)/(power of $S_1$) is equal to:

A beam of cathode rays is subjected to crossed Electric ($E$) and Magnetic field ($B$). The fields are adjusted such that the beam is not deflected. The specific charge ($e/m$) of the cathode rays is given by (where $V$ is the potential difference between cathode and anode):