Physics Test - ...

Two charges of +1 μC & + 5 μC are placed 4 cm apart, the ratio of the force exerted by both charges on each other will be :

Two filaments of same length are connected first in series then in parallel. For the same amount of main current flowing, the ratio of the heat produced is:

An electric bulb is designed to draw power P0 at voltage V0. If the voltage is V, it draws a power P, then-

The semi-major axes of the orbits of Mercury and Mars in the astronomical units are 0.387 and 1.524 respectively. If the time period of Mercury is 0.241 year, then the time period of mars will be:

Fountains usually seen in gardens are generated by a wide pipe with an enclosure at one end having many small holes. Consider one such fountain which is produced by a pipe of internal diameter 2cm2cm in which water flows at a rate 3ms−1. The enclosure has 100 holes each of diameter 0.05cm. The velocity of water coming out of the holes is (in ms−1).

A rectangular tank is placed on a horizontal ground and is filled with water to a height H above the base. A small hole is made on one vertical side at a depth D below the level of water in the tank. The distance x from the bottom of the tank at which the water jet from the tank will hit the ground is.

A wooden block of weight 20 N is pushed along a rough horizontal surface at constant speed by a horizontal force of 10 N. Which of the following is the coefficient of static friction between the block and the surface? (μs>μk)

A steady current is flowing in a circular coil of radius R, made up of a thin conducting wire. The magnetic field at the center of the loop is BL. Now, a circular loop of radius R/n is made from the same wire without changing its length, by unfolding and refolding the loop, and the same current is passed through it. If new magnetic field at the center of the coil is BC, then the ratio BL/BC is:

The graph, shown in the adjacent diagram, represents the variation of temperature (T) of two bodies, x and y having same surface area, with time (t) due to the emission of radiation. Find the correct relation between the emissive power (E) and absorptive power (a) of the two bodies: