WBJEE is a state level engineering entrance examination held to give admission to various engineering and medical courses.

In this article find **WBJEE Solved Physics & Chemistry Question Paper 2016 **for engineering entrance examination. Detailed solution of each question has been provided so that students do not lose their precious time in searching solutions of these questions.

Practicing previous years’ question papers and sample papers help aspirants in understanding exam pattern, question format, important topics and assessing preparation.

**33. For Fraunhoffer diffraction to occur **

(A) Light source should be at infinity

(B) Both source and screen should be at infinity

(C) Only the source should be at finite distance

(D) Both source and screen should be at finite distance

**Correct Option: (B)**

**Sol.**

For Fraunhoffer’s diffraction both source and screen should be at infinity

**34. The temperature of a blackbody radiation enclosed in a container of volume V is increased from 100°C to 1000°C. The heat required in the process is **

(A) 4.79×10^{–4} cal

(B) 9.21×10^{–5} cal

(C) 2.17×10^{–4} cal

(D) 7.54×10^{–4} cal

**Correct Option: ()**

**Sol.**

Information is not sufficient to solve this problem.

**Permutation and Combination: Practice Questions Set 1**

**35. A mass of 1kg is suspended by means of a thread. The system is (i) lifted up with an acceleration of 4.9 ms ^{-2}. (ii) lowered with an acceleration of 4.9 ms^{–2}. The ratio of tension in the first and second case is **

(A) 3:1

(B) 1:2

(C) 1:3

(D) 2:1

**Correct Option: (A)**

**Sol.**

**Category III (Q36 to Q40)**

**One or more answer(s) is (are) correct. Correct answer(s) will fetch marks 2. Any combination containing one or more incorrect answer will fetch 0 marks. If all correct answers are not marked and also no incorrect answer is marked then score = 2×number of correct answers marked/actual number of correct answers. **

**36. A rectangular coil carrying current is placed in a non-uniform magnetic field. On that coil the total **

(A) force is non-zero

(B) force is zero

(C) torque is zero

(D) torque is non-zero

**Correct Option(s): (A,D)**

**Sol.**

In most general cases correct options are A and D, but force and torque may be zero in some specific cases.

**37. A charged particle of mass m _{1} and charge q_{1} is revolving in a circle of radius r. Another charged particle of charge q_{2} and mass m_{2} is situated at the centre of the circle. If the velocity and time period of the revolving particle be v and T respectively, then **

**Correct Option: ()**

**Sol.**

The correct answer is not given in the option.

**38. The distance between a light source and photoelectric cell is d. If the distance is decreased to d/2 then **

(A) The emission of electron per second will be four times

(B) Maximum kinetic energy of photoelectrons will be four times

(C) Stopping potential will remain same

(D) The emission of electrons per second will be doubled

**Correct Option: (A,C)**

**Sol.**

Since there is no term of *d* so, the above equation will remain unchanged

Hence, KE_{max} as well as stopping potential remains unchanged

**Sequence and Series: Practice Questions Set 1**