Physics

If momentum (P), area (A) and time (T) are taken to be the fundamental quantities, then the dimensional formula for energy is :

A heat engine is involved with exchange of heat of 1915 J, –40 J, +125 J and –QJ, during one cycle achieving and efficiency of 50.0%. The value of Q is:

The displacement time graph of a particle executing SHM is given in figure: (sketch is schematic and not to scale)

Which of the following statements is/are true for this motion?
(a) The force is zero at t = 3T/4
(b) The acceleration is maximum at t = T
(c) The speed is maximum at t = T/4
(d) The P.E. is equal to K.E. of the oscillation at t = T/2

A 10μF capacitor is fully charged to a potential difference of 50 V. After removing the source voltage, it is connected to an uncharged capacitor in parallel. Now the potential difference across them becomes 20 V. The capacitance of the second capacitor is:

Two uniform circular discs are rotating independently in the same direction around their common axis passing through their centres. The moment of inertia and angular velocity of the first disc are 0.1 kg–m² and 10 rads⁻¹ respectively while those for the second one are 0.2 kg–m² and 5 rads⁻¹ respectively. At some instant, they get stuck together and start rotating as a single system about their common axis with some angular speed. The kinetic energy of the combined system is:

The height 'h' at which the weight of a body will be the same as that at the same depth 'h' from the surface of the earth is (Radius of the earth is R and effect of the rotation of the earth is neglected)

In a hydrogen atom, an electron makes a transition from (n + 1)th level to the nth level. If n >> 1, the frequency of radiation emitted is proportional to:

A wire carrying current I is bent in the shape ABCDEFA as shown, where rectangles ABCDA and ADEFA are perpendicular to each other. If the sides of the rectangles are of lengths a and b, then the magnitude and direction of magnetic moment of the loop ABCDEFA is:

An inductance coil has a reactance of 100Ω. When an AC signal of frequency 1000 Hz is applied to the coil, the applied voltage leads the current by 45°. The self-inductance of the coil is:

In the following, digital circuit, what will be the output at ' Z ', when the input (A, B) are (1,0), (0,0), (1,1), (0,1)