Which one of the following is the best shape of a solid metal rod to form the top end of a lightning conductor?
![NDA General Ability 21 April 2024 General Science - Physics Question 97 English Option 1](https://app-content.cdn.examgoal.net/fly/@width/image/6y3zli1lx58yq9h/3664e2e7-ad6b-4ef3-911b-6742425d757d/bb8a6a50-251b-11ef-aa8a-3911321f30bc/file-6y3zli1lx58yq9i.png?format=png)
![NDA General Ability 21 April 2024 General Science - Physics Question 97 English Option 2](https://app-content.cdn.examgoal.net/fly/@width/image/6y3zli1lx58zf7n/e4b5534d-bec6-4296-97f1-eb1d6fe34623/ced03130-251b-11ef-aa8a-3911321f30bc/file-6y3zli1lx58zf7o.png?format=png)
![NDA General Ability 21 April 2024 General Science - Physics Question 97 English Option 3](https://app-content.cdn.examgoal.net/fly/@width/image/6y3zli1lx590w74/cc8050b1-3fdd-483e-9e9f-aa6b2e48261f/f7be4000-251b-11ef-aa8a-3911321f30bc/file-6y3zli1lx590w75.png?format=png)
![NDA General Ability 21 April 2024 General Science - Physics Question 97 English Option 4](https://app-content.cdn.examgoal.net/fly/@width/image/6y3zli1lx58x4qi/a1ade1e4-d480-4a0c-b2f2-bc5ef0dd8a31/8f1a39a0-251b-11ef-aa8a-3911321f30bc/file-6y3zli1lx58x4qj.png?format=png)
Which of the following forces is/are fundamental in nature?
1. Gravitational force
2. Electromagnetic forces
3. Strong and weak nuclear forces
Select the correct answer using the code given below :
1 only
1 and 2 only
2 and 3 only
1, 2 and 3
A spherical shell of outer radius R and inner radius R/2 contains a solid sphere of radius R/2 (see figure). The density of the material of the solid sphere is ρ and that of the shell is ρ/2. What is the average mass density of the larger sphere thus formed?
![NDA General Ability 21 April 2024 General Science - Physics Question 95 English](https://app-content.cdn.examgoal.net/fly/@width/image/6y3zli1lx65taks/27889f80-5a1f-4cdc-9cc8-e511f066091f/31a3a9b0-259c-11ef-a2d7-7b1187e9ffd2/file-6y3zli1lx65takt.webp?format=webp)
3ρ/4
9ρ/16
7ρ/8
5ρ/8
The human eye is like a camera that has a lens with :
fixed focal length and fixed aperture size.
variable focal length and fixed aperture size.
fixed focal length and variable aperture size.
variable focal length and variable aperture size.