To an ac power supply of 220 V at 50 Hz, a resistor of $20~\Omega$, a capacitor of reactance $25~\Omega$ and an inductor of reactance $45~\Omega$ are connected in series. The corresponding current in the circuit and the phase angle between the current and the voltage is, respectively
A body weighs 48 N on the surface of the earth. The gravitational force experienced by the body due to the earth at a height equal to one-third the radius of the earth from its surface is :
Consider a water tank shown in the figure. It has one wall at $x=L$ and can be taken to be very wide in the z direction. When filled with a liquid of surface tension S and density $\rho$, the liquid surface makes angle $\theta_{0}$ $(\theta_{0}\ll1)$ with the x-axis at $x=L.$ If $y(x)$ is the height … Read more
The Sun rotates around its centre once in 27 days. What will be the period of revolution if the Sun were to expand to twice its present radius without any external influence? Assume the Sun to be a sphere of uniform density.
A wire of resistance R is cut into 8 equal pieces. From these pieces two equivalent resistances are made by adding four of these together in parallel. Then these two sets are added in series. The net effective resistance of the combination is:
A microscope has an objective of focal length 2 cm, eyepiece of focal length 4 cm and the tube length of 40 cm. If the distance of distinct vision of eye is 25 cm, the magnification in the microscope is
A model for quantized motion of an electron in a uniform magnetic field B states that the flux passing through the orbit of the electron is $n(h/e)$ where n is an integer, h is Planck’s constant and e is the magnitude of electron’s charge. According to the model, the magnetic moment of an electron in … Read more
De-Broglie wavelength of an electron orbiting in the $n=2$ state of hydrogen atom is close to(Given Bohr radius $=0.052~nm$)
An electron (mass $9\times10^{-31}$ kg and charge $1.6\times10^{-19}C)$ moving with speed $c/100$ ( $c=$ speed of light) is injected into a magnetic field $\overline{B}$ of magnitude $9\times10^{-4}T$ perpendicular to its direction of motion. We wish to apply an uniform electric field $\vec{E}$ together with the magnetic field so that the electron does not deflect from … Read more
Three identical heat conducting rods are connected in series as shown in the figure. The rods on the sides have thermal conductivity 2K while that in the middle has thermal conductivity K. The left end of the combination is maintained at temperature 3T and the right end at T. The rods are thermally insulated from … Read more