Physics

The velocity of a small ball of mass $M$ and density $d$ , when dropped in a container filled with glycerine becomes constant after some time. If the density of glycerine is $\frac{d}{2}$ , then the viscous force acting on 2 the ball will be:

The volume occupied by the molecules contained in 4.5Kg water at STP, if the intermolecular forces vanish away is :

Polar molecules are the molecules:

Two pendulums of length 121cm and 100cm start vibrating in phase. At some instant, the two are at their mean position in the same phase. The minimum number of vibrations of the shorter pendulum after which the two are again in phase at the mean position is :

For a plane electromagnetic wave propagating in $\mathrm{x}$ -direction, which one of the following combination gives the correct possible directions for electric field (E) and magnetic field (B) respectively?

A series LCR circuit with inductance $10\mathrm{H}$ , capacitance $10\mu \mathrm{F}$ , resistance $50\mathrm{\Omega }$ is connected to an ac source of voltage, $V=200\mathrm{s}\mathrm{i}\mathrm{n}?\left(100t\right)$ volt. If the resonant frequency of the LCR circuit is $v_0$ and the frequency of the ac source is $v$ , then

Given below are two statements : One is labelled as

Assertion (A) and the other is labelled as Reason (R).

Assertion (A): The stretching of a spring is determined by the shear modulus of the material of the spring.

Reason (R): A coil spring of copper has more tensile strength than a steel spring of same dimensions.

In the light of the above statements, choose the most appropriate answer from the options given below:

In a potentiometer circuit a cell of EMF $1.5\mathrm{V}$ gives balance point at $36\mathrm{c}\mathrm{m}$  length of wire. If another cel) of EMF 2.5 V replaces the first cell, then at what length of the wire, the balance point occurs?

A Wheatstone bridge is used to determine the value of unknown resistance X by adjusting the variable resistance Y as shown in the figure. For the most precise measurement of X, the resistance P and Q

A ball is projected with a velocity, $10{\mathrm{m}\mathrm{s}}^{-1}$ , at an angle of ${60}^{?}$  with the vertical direction, its speed at the highest pint of its trajectory will be :