Physics MCQs for NEET — Practice Questions with Answers

Let's match the concepts from Column I with their corresponding properties in Column II:

(I) Quantisation of charge: This is demonstrated by Milikan's oil drop experiment, which measured the charge of electrons (S).

(II) Wave nature of light: This is demonstrated by diffraction and interference experiments (P).

(III) Dual nature of matter: This is proposed by the de Broglie hypothesis, which states that particles exhibit both wave and particle properties (Q).

(IV) Particle nature of light: This is explained by the photoelectric effect, where light is shown to have particle-like properties (R).

So the correct matching is: I-S, II-P, III-Q, IV-R.

To solve this matching question, use the following formulas:

1. Energy of photon of wavelength \( \lambda \) is given by \( E = \frac{hc}{\lambda} \). So, I matches with R.
2. The de Broglie wavelength associated with a particle of momentum \( P \) is given by \( \lambda = \frac{h}{p} \). So, II matches with S.
3. Mass of photon in motion is given by \( m = \frac{hf}{c^2} \). So, III matches with Q.
4. The velocity of photon of energy \( E \) and momentum \( P \) is given by \( v = \frac{E}{p} \). So, IV matches with P.

Therefore, the correct matching is: I- R, II- S, III- Q, IV - P.

According to Lenz's law, the direction of the induced current is such that it opposes the change in magnetic flux that caused it. Since the current in the outer loop is increasing clockwise, the magnetic field due to this current is increasing out of the plane. To oppose this increase, the induced current in the inner loop must create a magnetic field into the plane. Hence, the induced current in the inner loop must be counterclockwise.

The total magnetic flux through the plane of the circular loop is zero because the magnetic field lines produced by the current in the loop are symmetric with respect to the plane of the loop. Since the loop lies in the X-Y plane, the net magnetic flux through this plane is zero.

Oppose any change

The self-inductance of a coil is directly proportional to the square of the number of turns. If the number of turns is made four times without any change in the length of the coil, the self-inductance becomes 4^2 = 16 times. Therefore, the self-inductance becomes sixteen times.