A charged shell of radius R carries a total charge Q. Given $$\phi $$ as the flux of electric field through a closed cylindrical surface of height h, radius r and with its center same as that of the shell. Here, center of the cylinder is a point on the axis of the cylinder which is equidistant from its top and bottom surfaces. Which of the following option(s) is/are correct?

[$$ \in $$₀ is the permittivity of free space]

Two identical moving coil galvanometers have 10$$\Omega $$ resistance and full scale deflection at 2$$\mu $$A current. One of them is converted into a voltmeter of 100 mV full scale reading and the other into an ammeter of 1 mA full scale current using appropriate resistors. These are then used to measure the voltage and current in the Ohm's law experiment with R = 1000$$\Omega $$ resistor by using an ideal cell. Which of the following statement(s) is/are correct?

Consider two identical galvanometers and two identical resistors with resistance R. If the internal resistance of the galvanometers R_c < R/2, which of the following statement(s) about anyone of the galvanometers is(are) true?

In the circuit shown below, the key is pressed at time t = 0. Which of the following statement(s) is (are) true?