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Hind brain: It has three Parts :

(i) Pons

(ii) Medulla

(iii) Cerebellum.

Functions:

(i) Pons has a centre for regulating the breathing rhythm.

(ii) Medulla controls involuntary functions like blood pressure, salivation, vomiting etc.

(iii) The cerebellum is responsible for

(a) Precision or co-ordination of voluntary actions.

(b) Maintaining the posture and balance of the body.

There are three components of hind-brain-Pons, cerebellum, medulla oblongata.

Functions of Pons: Relay centre, the pneumotaxic area of the respiratory centre. 

Functions of Cerebellum: Maintains equilibrium and co-ordinates muscular activities.

(a) A = πr²

\(\frac{dA}{dr}\) = π x 2r

= 2π x 3 = 6π cm

(b) A = πr²

\(\frac{dA}{dr}\) = 2πr

= 2π x 4 = 8πcm

(d) Microscopic organism

i. In glass, the speed of red ray is greater than that of violet ray.

ii. The speed of light in glass is less than that in water.

iii. The speed of light in water is greater than that in benzene.

iv. Rainbow occurs due to refraction, dispersion, internal reflection and again refraction of sunlight by water droplets.

v. In dispersion of sunlight by a glass prism, red ray is deviated the least.

In India, the alternating current changes direction after every 1/100 second, so the frequency of alternating current is 50 Hz.

Whenever the magnetic field lines linked with a coil change due to relative motion of a magnet and the coil, an induced current is produced in the coil. The magnitude of induced current is directly proportional to the rate of change of magnetic field lines.

The energy change that takes place in a D. C. motor is from electrical energy into mechanical energy. 

The speed of rotation of the coil in a D.C. motor can be increased by: (i) Increasing the strength of the current, (ii) Having more turns in the coil, (iii) Increasing the area of the coil, (iv) By increasing the strength of the magnetic field.

It is based on the principle that when an electric current is passed through a conductor placed normally in a magnetic field, a force acts on the conductor as a result of which the conductor begins to move. The direction of the force is obtained with the help of Fleming’s left hand rule.

Electrical energy to mechanical energy.

The lines of force, in this case, are concentric circles centered on the wire.

 The main properties are: 

(i) The magnetic lines of force are in the form of concentric circles around the conductor but as their distance from the conductor increases, the curvature of lines of force decreases. 

(ii) The direction of the magnetic lines of force reverses, if the direction of flow of current in the conductor reverses. 

(iii) With the increase of current in the conductor, the number of lines of force or the intensity of magnetic field also increases.

 (i) The time of change of magnetic flux, (ii) The strength of magnetic field. 

The important properties are: 

(i) The magnetic lines of force near the wire are nearly circular, especially at the points where the current enters or leaves the coil. 

(ii) At the centre of the coil, the lines of force are almost parallel to each other, showing that the magnetic field at the centre or the coil may be considered uniform.

(i) A static charge is not associated with a magnetic field around it. 

(ii) A moving charge is associated with a magnetic field around it. 

(iii) A current carrying conductor is associated with a magnetic field around it.

When the current in the wire is upwards, the needle will deflect with its north pole towards west. If the current in the wire is reversed, the north pole of the needle will deflect towards east.

Newton/(ampere-metre) or NA^-1m^-1

(i) The deflecting couple acting on the coil is maximum when the plane of the coil is parallel to the direction of magnetic field. 

(ii) The deflecting couple acting on the coil is minimum when the plane of the coil is normal to the direction of magnetic field.

To produce an induced current in a coil, a magnet is moved along the axis of coil. The magnitude of induced e.mi. depends on the strength of magnet.

The conductor is kept in N-S direction and its ends are connected to a battery, rheostat and a tapping key. When the key is open i.e., no current flows in the conductor, the needle points in N-S direction. As the key is pressed and a current passes in the conductor, the needle deflects. This shows that a magnetic field Exists around a current carrying conductor.

Whenever there is a change in number of magnetic lines of force associated with a coil, the e.m.f. induced in the coil lasts as long as the change takes place. This phenomenon is called electromagnetic induction.

The direction of magnetic field produced due to flow of current in a conductor can be determined by the right hand thumb rule. It states that if we hold the current carrying conductor in our right hand such that the thumb points in fire direction of current then the fingers encircling the wire indicate the direction of the magnetic lines of force.

 (i) This force F is maximum when the magnetic field due to flow of current in the conductor and the given magnetic field B are perpendicular to each other. 

(ii) This force F is zero when the magnetic field due to flow of current in the conductor is parallel to the given magnetic field B.

An electric motor is a device which converts the electrical energy into the mechanical energy. The working of an electric motor is based on the principle that a current carrying coil placed in a magnetic field with its plane parallel to the field, Experiences a deflecting couple. 

The direction of force will be reversed.

The current carrying solenoid when suspended freely, will rest along the N-S direction. The reason is that it will behave like a bar magnet, with N polarity at one face of solenoid and S polarity at the other face, depending upon the direction of current in the solenoid. 

Current carrying solenoid behaves like a bar magnet. At end in which direction of current is anticlockwise, behaves as north pole and where current is in clockwise direction behaves as south pole. Therefore on suspending it freely, set it self in North-South direction as bar magnet does.

Experimentally it is found that the magnitude of the force acting on a current carrying conductor kept in a magnetic field in a direction perpendicular to it, depends on the following factors: 

(i) The F is directly proportional to the length of the current carrying conductor, i.e., F ∝ l. 

(ii) F is directly proportional to the strength of the magnetic field, i.e., F ∝ B. 

(iii) F is directly proportional to the strength of the current flowing in the conductor, i.e., F ∝ i. 

Combining the above factors we find that: 

or F ∝ i Bl 

F = KiBl 

Factors on which the strength of the magnetic field of an electromagnet depends are: 

(i) The number of turns in the solenoid. If the number of turns in the solenoid increases or decreases, the magnetic intensity also increases or decreases. 

(ii) It is directly proportional to the strength of the current that flows in the turns of the solenoid. 

(iii) It is found to increase further if a soft iron piece, called core, is placed along the axis of the solenoid inside it. 

The Lenz’s law states that the direction of induced current is such that it opposes the cause which produces it.

The three conditions are: (i) Current in the conductor, (ii) Length of conductor, (iii) Strength of i magnetic field. The conductor will Experience no force if the direction of current in the conductor is parallel to the direction of magnetic field.

The magnitude of force acting on a current carrying conductor placed in a magnetic field depends on the following factors: 

(i) The force F is directly proportional to the strength of the current flowing in the conductor, i.e., F ∝ i. 

(ii) The force F is directly proportional to the strength of the magnetic field, i.e., F ∝ B; and 

(iii) The force F is directly proportional to the length of the conductor, i.e., F ∝ l.

Dynamo (or a.c. generator) is a device which converts mechanical energy into electrical energy. It works on the principle of electromagnetic induction. 

The mechanical energy changes to electrical energy. 

(i) The strength of current in the coil, (ii) The number of turns in the coil, (iii) The strength of the magnetic field.

Correct Answer is: (c) √(2H/3g)

As the masses of the body and the earth are comparable, they will both move towards their centre of mass, which remains stationary. When they meet, the body will have moved through a distance H/3 In both cases, the body moves with acceleration g, as H << R, i.e., the body is close to the earth’s surface.

Correct Answer is: (b) mgh, for h << R , (c) 1/2 mgR, for h = R

Work done = m x difference in gravitational potential.

ELSI which represents ethical, legal and social implications of biotechnology broadly covers the relationship between biotechnology and society with particular reference to ethical and legal aspects.

A fuse is usually made of tin or tin-copper alloy because it has Iow melting point.

The magnetic field produced by a current-carrying solenoid is similar to the magnetic field produced by a bar magnet.

(i) North pole. 

(ii) Electromagnet is a very strong magnet as compared to a permanent magnet.

1. Review Committee on Genetic Manipulation (RCGM) 

2. Genetic Engineering Approval Committee (GEAC)

Fuses of capacity 5 ampere or 15 ampere are commonly used in domestic electrical fittings.

Bioethics refers to the study of ethical issues emerging from advances in biology and medicine. It is also a moral discernment as it relates to medical policy and practice.

(b) Totipotent

Pineapple, banana, strawberry and potato.