JEE Mains 2023 : Best Question Collection in Physics | JEE Main Physics Test Series-1

1. An inductor coil stores 64 J of magnetic field energy and dissipates energy at the rate of 640 W when a current of 8 A is passed through it. If this coil is joined across an ideal battery, find the time constant of the circuit in seconds:

2. A series LCR circuit deriven by 300 V at a frequency of 50 Hz contains a resistance R= 3 kΩ, an inductor of inductive reactance XL = 250 πΩ and an unknown capacitor. The value of capacitance to maximize the average power should be:

3. In a Screw Gauge, fifth division of the circular scale coincides with the reference line when the ratchet is closed. There are 50 divisions on the circular scale, and the main scale moves by 0.5 mm on a complete rotation. For a particular observation, the reading on the main scale is 5 mm and the 20^th division of the circular scale coincides with reference line. Calculate the true reading.

4. Statement I :
By doping silicon semiconductor with pentavalent material, the electrons density increases.
Statement II :
The n-type semiconductor has net negative charge.
In the light of the above statements, choose the most appropriate answer from the options given below:

5. What equal length of an iron wire and a copper-nickel alloy wire, each of 2 mm diameter connected parallel to give an equivalent resistance of 3Ω ?
(Given resistivities of iron and copper nickel alloy wire are 12 μΩ  cm and 51 μΩ  cm respectively)

6. Inside a uniform spherical shell:

(a) the gravitational field is zero.
(b) the gravitational potential is zero.
(c) the gravitational field is same everywhere.
(d) the gravitational potential is same everywhere.
(e) all of the above.
Choose the most appropriate answer from the options given below:

7. The material filled between the plates of a parallel plate capacitor has resistivity 20092m The value of capacitance of the capacitor is 2 pF. If a potential difference of 40V is applied across the plates of the capacitor, then the value of leakage current flowing out of the capacitor is: (given the value of relative permitivity of material is 50)

8. The value of current in the 6Ω resistance is :

9. A deuteron and an alpha particle having equal kinetic energy enter perpendicular into a magnetic field. Let r_d and r_α be their respective radii of circular path. The value of ta is r_d/r_α equal to

10. A radioactive material decays by simultaneous emissions of two particles with half lives of 1400 years and 700 years respectively. What will be the time after which one-third of the material remains ? (Take In3 = 1.1)

11. The amount of heat needed to raise the temperature of 4 moles of a rigid diatomic gas from 0°C to 50°C when no work is done is…….. (R is the universal gas constant)

12. A butterfly is flying with a velocity 4√2 m/s in North-East direction. Wind is slowly blowing at 1 m/s from North to South. The resultant displacement of the butterfly in 3 seconds is :

13. A certain charge Q is divided into two parts qand (Q-q). How should the charges Q and q be divided so that q and (Q-q) placed at a certain distance apart experience maximum electrostatic repulsion?

14. A 25 m long antenna is mounted on an antenna tower. The height of the antenna tower is 75 m. The wavelength (in meter) of the signal transmitted by this antenna would be :

15. The stopping potential in the context of photoelectric effect depends on the following property of incident electromagnetic radiation :