WBJEE Phy & Chem Sample Paper - JEE MCQ

Two identical cells each of emf E and internal resistance r are connected in parallel with an external resistance R. To get maximum power developed across R, the value of R is

To write the decimal number 37 in binary, how many binary digits are required?

A junction diode has a resistance of 25Ω when forward biased and 2500Ω when reverse biased. The current in the diode, for the arrangement shown will be

If the electron in a hydrogen atom jumps from an orbit with level n₁ = 2 to an orbit with level n₂ = 1 the emitted radiation has a wavelength given by

What is the particle x in the following nuclear reaction:
 

An alternating current of rms value 10 A is passed through a 12Ω resistor. The maximum potential difference across the resistor is

Which of the following relation represent Biot-Savart’s law?

 are two vectors given by   The magnitude of the component of  is 

Given   What is the angle between  

The acceleration ‘a’ (in ms^–2) of a body, starting from rest varies with time t (in s) following the equation a = 3t + 4 The velocity of the body at time t = 2s will be

Figure below shows the distance-time graph of the motion of a car. If follows from the graph that the car is

Two particles have masses m & 4m and their kinetic energies are in the ratio 2: 1. What is the ratio of their linear momenta ?

The force F acting on a particle moving in a straight line is shown below. What is the work done by the force on the particle in the 1st meter of the trajectory ? 

If the kinetic energy of a body changes by 20% then its momentum would change by –

A bullet is fired with a velocity u making an angle of 60° with the horizontal plane. The horizontal component o the velocity of the bullet when it reaches the maximum height is

A particle is projected at 60° to the horizontal with a kinetic energy K. The kinetic energy at the highest point is 

The poisson’s ratio of a material is 0.5. If a force is applied to a wire of this material, there is a decrease in the cross-sectional area by 4%. The percentage increase in the length is :

Two spheres of equal masses but radii r₁ and r₂ are allowed to fall in a liquid of infinite column. The ratio of their terminal velocities is

Two massless springs of force constants K₁ and K₂ are joined end to end. The resultant force constant K of the system is

A spring of force constant k is cut into two equal halves. The force constant of each half is

Two rods of equal length and diameter have thermal conductivities 3 and 4 units respectively. If they are joined in series, the thermal conductivity of the combination would be

19 g of water at 30° C and 5 g of ice at – 20° C are mixed together in a calorimeter. What is the final temperature of the mixture? Given specific heat of ice = 0.5 cal g^–1(°C)^–1 and latent heat of fusion of ice = 80 cal g^–1

. It is difficult to cook rice in an open vessel by boiling it at high altitudes because of

The height of a waterfall is 50 m. If g = 9.8 ms^–2 the difference between the temperature at the top and the bottom of the waterfall is:

The distance between an object and a divergent lens is m times the focal length of the lens. The linear magnification produced by the lens is

A 2.0 cm object is placed 15 cm in front of a concave mirror of focal length 10 cm. What is the size and nature of the image?

A beam of monochromatic blue light of wavelength 4200 Å in air travels in water of refractive index 4/3. Its wavelength in water will be: