NTA JEE Main 31st January 2023 Shift 2

The number of turns of the coil of a moving coil galvanometer is increased in order to increase current sensitivity by 50%. The percentage change in voltage sensitivity of the galvanometer will be:

The $$H$$ amount of thermal energy is developed by a resistor in 10 s when a current of 4 A is passed through it. If the current is increased to 16 A, the thermal energy developed by the resistor in 10 s will be

A long conducting wire having a current $$I$$ flowing through it, is bent into a circular coil of $$N$$ turns. Then it is bent into a circular coil of $$n$$ turns. The magnetic field is calculated at the centre of coils in both the cases. The ratio of the magnetic field in first case to that of second case is:

An alternating voltage source $$V = 260 \sin(628t)$$ is connected across a pure inductor of 5 mH. Inductive reactance in the circuit is:

Match List I and List II
List I                    List II
A. Microwaves       I. Physiotherapy
B. UV rays               II. Treatment of cancer
C. Infra-red rays     III. Lasik eye surgery
D. X-rays                  IV. Aircraft navigation
Choose the correct answer from the option given below:

A microscope is focused on an object at the bottom of a bucket. If liquid with refractive index $$\dfrac{5}{3}$$ is poured inside the bucket, then microscope have to be raised by 30 cm to focus the object again. The height of the liquid in the bucket is:

If the two metals $$A$$ and $$B$$ are exposed to radiation of wavelength 350 nm. The work functions of metals $$A$$ and $$B$$ are 4.8 eV and 2.2 eV. Then choose the correct option

The radius of electron's second stationary orbit in Bohr's atom is $$R$$. The radius of 3$$^{rd}$$ orbit will be

Given below are two statements:
Statement I: In a typical transistor, all three regions emitter, base and collector have same doping level.
Statement II: In a transistor, collector is the thickest and base is the thinnest segment.
In the light of the above statements, choose the most appropriate answer from the options given below.

Given below are two statements
Statement I: For transmitting a signal, size of antenna ($$l$$) should be comparable to wavelength of signal (at least $$l = \dfrac{\lambda}{4}$$ in dimension).
Statement II: In amplitude modulation, amplitude of carrier wave remains constant (unchanged).
In the light of the above statements, choose the most appropriate answer from the options given below