Nuclei — Physics STD 12 Science — Question

A parallel plate capacitor has a plate separation of 0.01 mm and use a dielectric (whose dielectric strength is 19 KV/mm) as an insulator. The maximum potential difference that can be applied to the terminals of the capacitor is

(a) 190 V

(b) 290 V

(c) 95 V

(d) 350 V

Sky wave propagation is based on :

If mass-energy equivalence is taken into account, when water is cooled to form ice, the mass of water should:

As the quantum number increases, the difference of energy between consecutive energy levels?

Assertion  :  Zener diode works on a principle of breakdown voltage.

Reason      : Current increases suddenly after breakdown voltage.

(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.

Assertion : The comet do not obey Kepler's laws of planetary motion

Reason     :  The comet do not have elliptical orbit

(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.

Imagine that you are sitting in a room with your back to one wall and that an electron beam traveling horizontally from the back wall towards the front one is deflected towards the right. What is the direction of the magnetic induction field that exists in the room? 

Consider a magnetic dipole kept in the north to south direction. Let P₁, P₂, Q₁, Q₂ be four points at the same distance from the dipole towards north, south, east and west of the dipole respectively. The directions of the magnetic field due to the dipole are the same at:

Solid targets of different elements are bombarded by highly energetic electron beams. The frequency (f) of the characteristic X-rays emitted from different targets varies with atomic number Z as

(a) f ∝

(b) f ∝

(c) f ∝ Z

(d) f ∝

The electrical circuit used to get smooth dc output from a rectifier circuit is called

(a) Oscillator

(b) Filter

(c) Amplifier

(d) Logic gates