Higher Secondary School

Solutions to Irodov problems

Problems In General Physics, 
I.E. Irodov
Part-I Physical Fundamentals in Mechanics.

Chapter 1.1 Kinematics.  

10 interesting problems in elementary mechanics

This post intends to provide 40 interesting problems in elementary mechanics from IE Irodov, Problems in general physics that I solved in last couple weeks. Note that another 30 problems (additional 12 at hand) which has been solved will be uploaded after they are scanned, shortly.

Basic Concepts.
In this class today we will discuss the subject of “kinematics” briefly and solve some problems, based on the same. 

The motion of objects are studied under the heading “mechanics”.

♣ Mechanics is called “kinematics” if we study about the “nature of motion” without regard to what factors are causing such motion. 

♣ In addition to kinematics, when we focus our attention to study the factors that cause motion, such is named as dynamics. 

In kinematics today we will discuss a few problems that will cover the topics of …

I.S.C. Board Question Paper. Physics, Class XII – 2009 ( C.I.S.C.E. )

Question 1 
Answer all question briefly and to the point.

(i)
Explain the statement ‘relative permittivity of water is 81’.

(ii)
Draw (at least three) electric lines of force due to an electric dipole.

(iii)
Find the value of resistance X in the circuit below so that the junction M and N are at the same potential.

(ix)
A ray LM of monochromatic light incident normally on one refracting surface AB of a regular glass prism ABC emerges in air from the adjacent surface AC as shown in Figure. Calculate the refractive index of the material of the prism.

SECTION A
(Answer any two questions)

Question 2 
(a)
With the help of a labeled diagram, obtain an expression for the electric field intensity ‘E’ at a point P in broad side position (i.e. equatorial plane) of an electric dipole.

Question 3
(c)
(i) State any two differences between a moving coil galvanometer and a tangent galvanometer.

(ii) What is the use of a Cyclotron?

SECTION C
(Answer any two questions)

Question 8
(a)
Electrons, initially at rest, are passed through a potential difference of 2 kV. Calculate their:

(i) Final velocity and

(ii) de Broglie wavelength

Physics midterm exam, for class XII (ISC-II) for C.I.S.C.E. board.

PART-I
Total 10 marks
Each question carries 1 mark.  Answer all. (10)              

Question 1 [Objective, 10 X 1]
(a)
Which of the following drops faster?

A. an electric dipole‘s electric field                      B. an electric dipole‘s electric potential

C. a point charge’s electric field                            D. a point charge’s electric potential

Physics midterm, for class XII, for C.B.S.E. and State boards.

Question 1
Which of the following drops faster?

A. An electric dipole’s electric field                      B. An electric dipole’s electric potential

C. A point charge’s electric field                            D. A point charge’s electric potential

Question 4
Chose the correct one

A. Kirchhoff’s loop rule is applied to a junction of incoming and outgoing current?

B. According to Kirchhoff’s loop rule a junction of incoming and outgoing current carries a potential proportional to the amount of current flowing through the junction.             

C. Kirchhoff’s junction rule can be applied to a single current carrying path in any electric circuit.

D. The potential drop in a loop in any electric circuit is zero and its based on conservation of energy.

Question 5
Chose the correct one

A. Resultant of capacitance in series is more than individual resistances

B. Current division works on the basis of direct proportionality of resistances

C. Voltage division works on the basis of direct proportionality of resistances

D. Resistors in series will add up

PART-B

Question 2
Describe de-Broglie wavelength in 1 or 2 lines and write the formula that we use for this idea.

Question 6
Give example of 3 conservative forces. A conservative force is defined through the following; “The work done in a conservative force field during a circular voyage is zero, as such work done are independent of the path taken”.

PART-C

Question 1
Define electric current and electric current density. State and explain Ohm’s law. Derive an expression for drift velocity.

Question 7
Derive the magnetic field B of a toroid by using Ampere’s circuital law.

PART-D

Question 13.
State the mirror equation and thin lens formula. Derive the lens formula with a suitable diagram.

Physics midterm preparatory exam, (+2) 2nd year, C.B.S.E. and state boards.

PART-A
Answer all the following questions, 1 mark each, 1 X 10
Question 1
Which of the following is a vector?

A. An electric dipole’s electric potential          B. An electric dipole’s charge

C. Electric current                                                D. Electric current density

Question 2
Which medium will have a stronger electrostatic force between 2 charges?

A. Medium with ε = 12                                      B. Medium with ε = 102

C. Medium with ε = 81                                      D. Free space, ε = ε0.

Question 3
Pick only the correct one “between an electron and a positron”

A. The electron has more specific charge.

B. The positron has more specific charge.

C. Both have equal specific charge.

D. For some particles specific charge can’t be determined, so it can’t be said electron or positron has more specific charge.

Question 4
Chose the correct one

A. Kirchhoff’s loop rule is applied to a junction of incoming and outgoing current.

B. According to Kirchhoff’s loop rule a junction of incoming and outgoing current carries a potential proportional to the amount of current flowing through the junction.             

C. Kirchhoff’s Junction rule can be applied to a single current carrying path in any electric circuit.

D. The potential drop in a loop in any electric circuit is zero and its based on conservation of energy.

Question 5
Chose the correct one

A. Resultant of capacitance in series in more than individual resistances

B. Current division works on the basis of direct proportionality of resistances

C. Voltage division works on the basis of direct proportionality of resistances

D. Resistors in series will add up