List of top Questions asked in WBJEE

What are the charges stored in the $ 1\,\mu\text{F} $ and $ 2\,\mu\text{F} $ capacitors in the circuit once current becomes steady?

Which one among the following compounds will most readily be dehydrated under acidic condition?

Manufacturers supply a zener diode with zener voltage $ V_z=5.6\,\text{V} $ and maximum power dissipation $ P_{\max}=\frac14\,\text{W} $. This zener diode is used in the circuit shown. Calculate the minimum value of the resistance $ R_s $ so that the zener diode will not burn when the input voltage is $ V_{in}=10\,\text{V} $.

Two charges $ +q $ and $ -q $ are placed at points $ A $ and $ B $ respectively which are at a distance $ 2L $ apart. $ C $ is the midpoint of $ AB $. The work done in moving a charge $ +Q $ along the semicircle CSD ($ W_1 $) and along the line CBD ($ W_2 $) are

A piece of granite floats at the interface of mercury and water. If the densities of granite, water and mercury are $ \rho, \rho_1, \rho_2 $ respectively, the ratio of volume of granite in water to that in mercury is

One end of a steel wire is fixed to the ceiling of an elevator moving up with an acceleration $ 2\,\text{m/s}^2 $ and a load of $ 10\,\text{kg} $ hangs from the other end. If the cross-section of the wire is $ 2\,\text{cm}^2 $, then the longitudinal strain in the wire is given. (Take $ g=10\,\text{m/s}^2 $ and $ Y=2.0\times10^{11}\,\text{N/m}^2 $).

The number of undecayed nuclei $ N $ in a sample of radioactive material as a function of time $ t $ is shown in the figure. Which of the following graphs correctly shows the relationship between $ N $ and the activity $ A $?

The variation of density of a solid cylindrical rod of cross-sectional area $ a $ and length $ L $ is $ \rho=\rho_0 \frac{x^2}{L^2} $, where $ x $ is the distance from one end. The position of its centre of mass from $ x=0 $ is

A diode is connected in parallel with a resistance as shown in the figure. The most probable current (I)–voltage (V) characteristic is

For an ideal gas, a cyclic process ABCA as shown in the P–T diagram. When represented in P–V plot, it would be

Which logic gate is represented by the following combinations of logic gates?

Figure shows the graph of angle of deviation $ \delta $ versus angle of incidence $ i $ for a light ray striking a prism. The prism angle is

Six vectors $ \vec{a},\vec{b},\vec{c},\vec{d},\vec{e},\vec{f} $ have magnitudes and directions shown. Which statement is true?

Three different liquids are filled in a U-tube as shown. Their densities are $ \rho_1, \rho_2, \rho_3 $ respectively. From the figure we may conclude that

The velocity-time graph for a body of mass $ 10\,\text{kg} $ is shown. Work done on the body in the first two seconds of motion is

Acceleration-time ($a-t$) graph of a body is shown. The corresponding velocity-time ($v-t$) graph is

Temperature of a body $ \theta $ is slightly more than the temperature of the surroundings $ \theta_0 $. Its rate of cooling $ R $ versus temperature $ \theta $ graph should be