wbjeeb.in Model Question Paper 2013 : West Bengal Joint Entrance Examinations Board

Name of the Organisation : West Bengal Joint Entrance Examinations Board (wbjeeb.in)
Type of Announcement : WBJEE-2013 Model Question

Model Questions WBJEE 2013 : https://www.indianjobtalks.in/uploads/6932-Model_Questions_WBJEE2013.pdf
Home Page : http://www.wbjeeb.in/

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Model Question Paper (Biological Sciences) : https://www.indianjobtalks.in/25775.html

Model Questions WBJEE 2013 :
At given instant of time, two radioactive elements P and Q have the same number of atoms. It is also known that the mean-life time of P is the same as the half-life time of Q. then which of the following is correct?
A. The decay rate of P is larger than that of Q
B. The decay rate of Q is larger than that of P
C. The decay constant of P is less than that of Q
D. The decay rate of P and Q will be same initially

An object is moving away from a vertical concave mirror of focal length 25 m. When the distance of the object is 100 m, the velocity of the object is 5 m/s and it accelerates at the rate of 2 m/s2. The distance of the object from the image after 5 sec is
A. 300 m B. 120 m C. 150 m D. 90 m

In hydrogen spectrum, the longest wavelength in the U-U series is 122×10-9 meter. This corresponds to a transition of electron from the level
A. n = 2 to n = 1 B. n = 3 to n = 2 C. n = 4 to n = 3 D. n = 3 to n = 1

If E = energy, G = gravitational constant, I = impulse and M = mass,the dimension of (GIM2)/E2 are same as that of
A. mass B. length C. time D. force

A car moving at a speed of 20 km/hr stops by applying brakes after travelling 5m. If the same car is moving at 40 km/hr, the stopping distance after applying brakes will be
A. 10m B. 20m C. 5m D. 1m

Two soap bubbles have radii in the ratio 2:1. What is the ratio of the excess pressure inside them?
A. 2:1 B. 1:2 C. 1:4 D. 4:1

The second overtone of an open pipe is in resonance with the first overtone of a closed pipe of length 2m. Length of the open pipe is
A. 1m B. 2m C. 4m D. 8m

The electrostatic potential energy between proton and electron separated by 1?? is
A. -14.4 eV B. -13.6 eV C. -27.2 eV D. -1.44 eV

Category II (2 marks, 1 correct answer)
A car P moves with a velocity V towards a stationary observer M. Another car Q moves away from M in the same direction with same velocity V. Both the cars continuously blow whistles of same frequency 380 Hz and the observer M hears 20 beats /sec. Assume the velocity of sound is 340 m/sec. The value of V in m/sec is
A. 11.3 B. 17.0 C. 20.9 D. 8.5

A solid homogeneous cube floats at the interface of two liquids, mercury and water, kept in a container such that the lower portion of the cube is immersed in mercury and the upper portion is in water. The density of the material of the cube is 7.3 gm/cc and those of mercury and water are respectively 13.6 gm/cc and 1.0 gm/cc. Then the % of volume of the cube immersed in mercury is
A. 70% B. 68% C. 50% D. 73%

The dimension of a quantity is given by ML2T-2 I-2, where M is mass, L is length, T is time, and I is electric current. Which of the following quantities has this dimension?
A. Capacitor B. Inductance C. Magnetic Flux D. Electric Flux

A spherical black body of radius 12cm radiates 450W power at 500?K. If the radius is halved and temperature doubled, the power radiated in watts would be
A. 225 B. 450 C. 900 D. 1800

Category III (2 marks, 1 or more than 1 correct answer)
2. An experiment to measure Y with a set of four wires of same material and same mass but of different lengths and diameters were performed using a frictionless pulling arrangement as shown. Different masses were used to create tension for the measurement of length-extension of each wire. In this experiment, which of the following quantities do/does not vary linearly?
A. For a given applied mass, the extension of length vs diameter of wire
B. For a given applied mass, the extension of length vs length of the wires
C. For all wires, the extension of length versus applied mass
D. For same amount of extension of length of all wires, length of wire vs. the elastic potential energy

A compound that behaves like a monobasic acid as well as an inorganic ester is:
A. ethyl hydrogen phthalate
B. potassium hydrogen tartarate
C. trimethyl oxonium tetrafluoroborate
D. ethyl hydrogen sulphate

Preparation of pentaerythritol from acetaldehyde and formaldehyde requires:
A. first Claisen condensation and then aldol condensation
B. first Perkin reaction and then haloform reaction
C. first aldol condensation and then Cannizaro reaction
D. none of these

Category III (2 marks, 1 or more than 1 correct answer)
Which of the following do not play a significant role in ozone depletion?
A. Oxides of Nitrogen B. Sulfur dioxide C. Carbon monoxide D. Freons

A gas described by the van der Waal’s equation
A. behaves similar to an ideal gas in the limit of large molar volume
B. behaves similar to an ideal gas in the limit of high pressure values
C. is characterized by van der Waal’s coefficients that are dependent on the identity of the gas
D. has pressure lower than the pressure exerted by the same gas behaving ideally