NTA JEE Main 29th January 2023 Shift 1

Ratio of thermal energy released in two resistor $$R$$ and $$3R$$ connected in parallel in an electric circuit is:

A single current carrying loop of wire carrying current $$I$$ flowing in anticlockwise direction seen from $$+ve$$ z direction and lying in $$xy$$ plane is shown in figure. The plot of $$\hat{j}$$ component of magnetic field $$(B_y)$$ at a distance $$a$$ (less than radius of the coil) and on $$yz$$ plane vs $$z$$ coordinate looks like

The magnitude of magnetic induction at mid-point $$O$$ due to current arrangement as shown in figure will be

Find the mutual inductance in the arrangement, when a small circular loop of wire of radius $$R$$ is placed inside a large square loop of wire of side $$L(L \gg R)$$. The loops are coplanar and their centres coincide: 

Which of the following are true?
A. Speed of light in vacuum is dependent on the direction of propagation.
B. Speed of light in a medium is independent of the wavelength of light.
C. The speed of light is independent of the motion of the source.
D. The speed of light in a medium is independent of intensity.
Choose the correct answer from the question given below:

The threshold wavelength for photoelectric emission from a material is $$5500$$ $$\text{\AA}$$. Photoelectrons will be emitted, when this material is illuminated with monochromatic radiation from a
A. 75 W infra-red lamp
B. 10 W infra-red lamp
C. 75 W ultra-violet lamp
D. 10 W ultra-violet lamp
Choose the correct answer from the options given below:

If a radioactive element having half-life of $$30$$ min is undergoing beta decay, the fraction of radioactive element remains undecayed after $$90$$ min will be:

Which of the following statement is not correct in the case of light emitting diodes?
A. It is a heavily doped p-n junction.
B. It emits light only when it is forward biased.
C. It emits light only when it is reverse biased.
D. The energy of the light emitted is equal to or slightly less than the energy gap of the semiconductor used.
Choose the correct answer from the options given below:

If the height of transmitting and receiving antennas are $$80$$ m each, the maximum line of sight distance will be:
Given: Earth's radius $$= 6.4 \times 10^6$$ m.

A tennis ball is dropped on to the floor from a height of $$9.8$$ m. It rebounds to a height $$5.0$$ m. Ball comes in contact with the floor for $$0.2$$ s. The average acceleration during contact is ______ m s$$^{-2}$$. [Given $$g = 10$$ m s$$^{-2}$$]