NTA JEE Main 8th April 2017 Online

Time ($$T$$), velocity ($$C$$) and angular momentum ($$h$$) are chosen as fundamental quantities instead of mass, length and time. In terms of these, the dimensions of mass would be:

Which graph corresponds to an object moving with a constant negative acceleration and a positive velocity?

An object is dropped from a height $$h$$ from the ground. Every time it hits the ground it loses 50% of its kinetic energy. The total distance covered as $$t \to \infty$$ is:

A uniform disc of radius $$R$$ and mass $$M$$ is free to rotate only about its axis. A string is wrapped over its rim and a body of mass $$m$$ is tied to the free end of the string as shown in the figure. The body is released from rest. Then the acceleration of the body is:

Moment of inertia of an equilateral triangular lamina $$ABC$$, about the axis passing through its centre $$O$$ and perpendicular to its plane is $$I_0$$ as shown in the figure. A cavity $$DEF$$ is cut out from the lamina, where $$D$$, $$E$$, $$F$$ are the mid points of the sides. Moment of inertia of the remaining part of lamina about the same axis is:

In a physical balance working on the principle of moments, when 5 mg weight is placed on the left pan, the beam becomes horizontal. Both the empty pans of the balance are of equal mass. Which of the following statements is correct?

If the Earth has no rotational motion, the weight of a person on the equator is $$W$$. Determine the speed with which the earth would have to rotate about its axis so that the person at the equator will weigh $$\frac{3}{4}W$$. The radius of the Earth is 6400 km and $$g = 10$$ m s$$^{-2}$$.

A compressive force, $$F$$ is applied at the two ends of a long thin steel rod. It is heated, simultaneously, such that its temperature increases by $$\Delta T$$. The net change in its length is zero. Let $$l$$ be the length of the rod, $$A$$ its area of cross-section, $$Y$$ its Young's modulus, and $$\alpha$$ its coefficient of linear expansion. Then, $$F$$ is equal to:

In an experiment, a sphere of aluminium of mass 0.20 kg is heated up to 150°C. Immediately, it is put into water of volume 150 cc at 27°C kept in a calorimeter of water equivalent to 0.025 kg. The final temperature of the system is 40°C. The specific heat of the aluminium is (take 4.2 Joule = 1 calorie):

An engine operates by taking $$n$$ moles of an ideal gas through the cycle $$ABCDA$$ shown in figure. The thermal efficiency of the engine is: (Take $$C_v = 1.5R$$, where $$R$$ is gas constant)