An electric motor operating at a 100 V D.C. supply draws a current of 12 A. If the efficiency of the motor is 30%, calculate the resistance of its winding.

The sun maintains its shine because of the

Two long and parallel straight wires A and B carrying currents of 8.0 A and 5.0 A in the same direction are separated by a distance of 4.0 cm. Estimate the force on 10 cm length of wire B:

At a certain place on earth, the north tip of the magnetic needle of a dip circle placed in the plane of magnetic meridian points \( 60^{\circ} \) below the horizontal. The horizontal component of the earth's magnetic field is measured to be 0.16 G. The magnitude of the earth's magnetic field at the location is:

The following table gives the lenght, diameter and appiled potential difference of four copper wires, A, B, C, D, across their ends. Arrange the wires in correct order of the increasing electric field.

Wire	Length	Diameter	Potential difference
(A) Wire A	l	3d	V
(B) Wire B	2l	d	V
(C) Wire C	3l	2d	2V
(D) Wire D	3l	2d	V

Choose the correct answer from the options given below:

The atomic numbers and mass numbers of the nuclei of hydrogen, deuterium and tritium, respectively are in the ratio

If the dielectric constant and dielectric strength be denoted by k and x respectively, then good capacitor must have :

Two parallel plate capacitors of capacitances \(2 \mu F\) and \(3 \mu F\) are joined in series and connected to a battery of \(V\) volts. The values of potential across the two capacitors V1 and V2 and energy stored in them U1 and U2 are related as :

Read the passage carefully and answer the questions based on the passage:
The number of reacting species (atoms, ions or molecules) taking part in an elementary reaction, which must collide simultaneously in order to bring about a chemical reaction is called molecularity of a reaction. In the rate equation Rate \(=k[\mathrm{~A}]^x[\mathrm{~B}]^y\)
\(x\) and \(y\) indicate how sensitive the rate is to the change in concentration of A and B, respectively. Sum of these exponents, i.e., \(x +y\) gives the overall order of a reaction where \(x\) and \(y\) represent the order with respect to the reactants A and B respectively. Hence, the sum of powers of the concentration of the reactants in the rate law expression is called the order of that chemical reaction. For a first order reaction, the concentration of the reactant varies as \([\mathrm{R}]=[\mathrm{R}]_0 e^{-k t}\)
Which of the following is a zero order reaction?

Which of the following amine will not undergo acylation reaction?

In a circuit where current 3I enters at A, with semicircular sections ABC and ADC of equal radii r, resistances 2R and R respectively, the magnetic field at the center is :

Which of the following is a vertex of the positive region bounded by the inequalities:
\(4 x+y \geq 80 ; \quad 2 x+y \geq 60 ; \quad x, y \geq 0\)

Which of the following enzyme is used during isolation of DNA from fungal cells?