# WBJEE 2015 Solved Physics Question Paper – Part 6

Find WBJEE 2015 Solved Physics Question Paper – Part 6 in this article. This paper consists of 5 questions (#26 to #30) from WBJEE 2015 Physics paper. Detailed solution of these questions has been provided so that students can match their solutions.

Importance of Previous Years’ Paper:

Previous years’ question papers help aspirants in understanding exam pattern, question format, important topics and assessing preparation. It has also been seen that sometimes questions are repeated in WBJEE Exam. So, this paper will certainly boost your confidence.

WBJEE is a common entrance examinations held at state level for admission to the Undergraduate Level Engineering and Medical courses in the State of West Bengal. The Physics section of WBJEE 2015 engineering entrance exam consists of 40 questions.

26. Two particles A and B having different masses are projected from a tower with same speed. A is projected vertically upward and B vertically downward. On reaching the ground

(A) velocity of A is greater than that of B

(B) velocity of B is greater than that of A

(C) both A and B attain the same velocity

(D) the particle with the larger mass attains higher velocity

Ans : (C)

Sol.

27. The work function of metals is in the range of 2 eV to 5eV. Find which of the following wavelength of light cannot be used for photoelectric effect.

(Consider, Planck constant = 4×10–15eVs, velocity of light = 3×108m/s)

(A) 510 nm

(B) 650 nm

(C) 400 nm

(D) 570 nm

Ans: (B)

Sol.

The work function of metal is given as:

So, the wavelength of light that cannot be used for photoelectric effect is 650 nm.

WBJEE 2016 Solved Physics and Chemistry Question Paper

28. A thin plastic sheet of refractive index 1.6 is used to cover one of slits of a double slit arrangement. The central point on the screen is now occupied by what would have been the 7th bright fringe before the plastic was used. If the wavelength of light is 600 nm, what is the thickness (in µm) of the plastic?

(A) 7

(B) 4

(C) 8

(D) 6

Ans: (A)

Sol.

29. The length of an open organ pipe is twice the length of another closed organ pipe. The fundamental frequency of the open pipe is 100 Hz. The frequency of the third harmonic of the closed pipe is

(A) 100 Hz

(B) 200 Hz

(C) 300 Hz

(D) 150 Hz

Ans: (A)

Sol.

30. A 5 µF capacitor is connected in series with a 10 µF capacitor. When a 300 Volt potential difference is applied across this combination, the energy stored in the capacitors is

(A) 15 J

(B) 1.5 J

(C) 0.15 J

(D) 0.10 J

Ans : (C)

Sol.

Let us assume that,

C1=5 µF

C2=10µF

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