JUNE 2024 — Physics STD 12 Science — Question

A cube of side l is placed in a uniform field E, where E = E. The net electric flux through the cube is

(a) Zero

(b)

(c) 4

(d) 6

Electric charges of +10μC, + 5μC, -3μC and +8 μC  are placed at the corners of a square of side  m. the potential at the centre of the square is

(a) 1.8 V

(b)  V

(c) 1.8

(d) 1.8  V

In electromagnetic spectrum, the component whose wavelength is minimum is:

The electrostatic potential due to a point charge is directly proportional to:

Two capacitors of 1mF  and 2mF  are connected in series, the resultant capacitance will be

(a) 4μF

(b)

(c)

(d) 3 μF

A uniform wire of resistance R is uniformly compressed along its length, until its radius becomes n times the original radius.  Now resistance of the wire becomes

(a)

(b)

(c)

(d) nR

For a medium, refractive indices for violet, red and yellow are 1.62, 1.52 and 1.55 respectively, then dispersive power of medium will be

(a) 0.65

(b) 0.22

(c) 0.18

(d) 0.02

A plane wavefront (λ = 6   falls on a slit 0.4 mm  wide. A convex lens of focal length 0.8 m  placed behind the slit focusses the light on a screen. What is the linear diameter of second maximum

(a) 6mm

(b) 12 mm

(c) 3 mm

(d) 9 mm

A capacitor of capacitance 5 micro farads is charged to 1000 volts. The energy stored on the capacitor will be (in joules):