Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

Out of the following, the one whose frequency is minimum is:

The half-life of a radioactive substance is 3.6 days. How much of 20 mg of this radioactive substance will remain after 36 days(a) 0.0019 mg(b) 1.019 mg(c) 1.109 mg(d) 0.019 mg

Which is reverse biased diode

Assertion   :   In practical application, power rating of resistance is not important.
Reason      : Property of resistance remain same even at high temperature.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

A body is positively charged, it implies that:

'Mirage' is a phenomenon due to(a) Reflection of light(b) Refraction of light(c) Total internal reflection of light(d) Diffraction of light

(1): The dielectric medium between the plates of a parallel plate capacitor lowers the potential difference between the plates without a battery.
(2): The maximum electric field that a dielectric can withstand without causing it to break down is dielectric strength.