The circuits where transformers are used :

In a plane electromagnetic wave, the electric field oscillates sinusoidally at a frequency of \( 3 \times 10^{10} \text{ Hz} \) and its amplitude is 30 V/m. The amplitude of the oscillating magnetic field is:

The ratio of radii of the nuclei with the mass numbers given as 2, 16, 54 and 128, respectively, will be

An external voltage is applied across a diode such that the n-side is positive and the p-side is negative. As a result,
(A) the barrier height decreases
(B) the barrier height increases
(C) the depletion region widens
(D) the depletion region width decreases
(E) no change in barrier height
Choose the correct answer from the options given below:

Match List-I with List-II

List-I (Physical quantity)	List-II (Unit)
(A) Electric flux	(I) V m−1
(B) Polarisation	(II) kg m−1⁢ s−2
(C) Electric field	(III) V m
(D) Energy density	(IV) C m−2

Choose the correct answer from the options given below:

The force between two small charged spheres having charges of \( 0.2 \, \mu\text{C} \) and \( 0.6 \, \mu\text{C} \) placed 0.6 m apart in air will be:

Which of the following statements are correct?
A. Electric field lines are always perpendicular to equipotential lines.
B. A zero electric field inside a conducting sphere does not mean that the potential gradient is also zero.
C. The resultant of two electric fields is determined by vector addition of the two field strengths.
D. If the field lines get closer together at any place, it means that the field strength is decreasing.
E. The resultant potential at a point is just the sum of the individual potentials.
Choose the correct answer from the options given below:

Function \(f(x)=x^x, x>0\) decreases on the interval

The presence or absence of hydroxyl group on which carbon is ribose sugar differentiate RNA and DNA?

Which of the following does not have any place in the ecological pyramids?

Answer the question on the basis of passage given below :
A colloid is a heterogeneous system in which a substance is dispersed (dispersed phase) as fine particles in another substance called dispersion medium.
Their particle size is intermediate between that of pure solutions (less than 1 nm) and suspensions (greater than 1000 nm). They are known for interesting properties such as enormous surface area, Tyndall effect, Brownian motion etc.
They are widely used in industries and day to day life.
Some prominent uses of colloids are those in smoke precipitators, purification of water, medicines, cleansers etc.
Which of the following statement is false regarding charge on sol particles ?

An emf \( E = 200 \sin 300t \text{ volt} \) is applied across an inductor coil having a resistance of \( 1.0 \text{ } \Omega \). If the maximum current is found to be 10 A, then the value of inductance is approximately:

Light travels in the form of photons. Identify the correct statements
(A) Photons travel with the velocity of light in vacuum.
(B) The rest mass of photons is taken as zero.
(C) Photons have energy which depends on frequency.
(D) Photons have a momentum inversely dependent on frequency.
Choose the correct answer from the options given below.