## Homework for XI/group A/SHIKSHA/Saturday/29-09-2018

Q1.  A force of 200 N is applied to a block of mass 20 kg on an inclined plane at 53 º with the horizontal .

(i)  What will be the acceleration of the block in downward direction ?

(II) How much force is required to move it in up along the plane ?

(iii) How much force is required to keep the body at rest on the inclined plane ?

Q3. A 20 kg block is initially at rest on a rough horizontal surface. A horizontal   force of 75 N is required to set the block in motion. After it is in motion, ahorizontal force of 60 N is required to keep the block moving  with constant speed. Find the coefficient of static  and kinetic friction .

Q4. A body of 5 kg weight kept on a rough inclined plane of angle 30º starts  sliding with a constant velocity. Then find the coefficient of friction . (assume  g = 10 m/s²)

Q5. Define the following terms

Sliding friction , limiting friction , angle of friction , coefficient of kinetic friction , angle of repose .

## Homework for XII/group B/VIDYARTHI/Friday/28-09-2018

Q1. An AC is given as   i = 10 sin ωt  with .0.02 sec as time period . Draw the AC showing the mean value and RMS value .

Q2. Prove that mean value for the full cycle of an AC is zero .

Q3. The RMS voltage  of the power supply that we use in India is 220 volt . What will be it’s peak value ? Also find the mean value .

Q4. Why AC is dangerous ?

Q5.  An AC   i = 10 sin 314t  is connected to a resistor of resistance 10 Ω   . Find the potential drop across the resistor .

Q6.  An AC   i = 10 sin 314t  is connected to an inductor  of self induction of  10 Henry  . Find the potential drop across the inductor .

Q7.  An AC   i = 10 sin 314t  is connected to a capacitor of 10 μF   . Find the potential drop across the capacitorr .

Q8. Draw the graph showing the variation between

(I) inductive reactance and angular frequency

(ii) capacitive reactance and angular frequency

## Homework for XI / group B / Vidyarthi /Friday?28-09-2018

Q1.  A force of 200 N is applied to a block of mass 20 kg on an inclined plane at 37 º with the horizontal .

(i)  What will be the acceleration of the block in downward direction ?

(II) How much force is required to move it in up along the plane ?

Q2.  The coefficient of friction for a block of mass 10 kg and a surface is  0.3 .  Find the force of friction and the acceleration of the block if the applied force is 10 N , 30 N , 50 N and 0 N .

Q3. Explain why

(i) rolling friction helps in motion

(ii) static friction is a self adjusting force

Q4. State the laws of friction

Q5. Define the following terms

Sliding friction , limiting friction , angle of friction , coefficient of kinetic friction , angle of repose .

## Welcome

Hello students!

I have started my new blog named physics 365.com , which was earlier the name of my website . Due to some technical issues I have to repair that website and in place of it , starting this blog to interact with you.

You can ask your questions and doubts . I will definitely try to give you the answer.

I regularly submit the home works for my different batches at my institution named VIDYARTHI and SHIKSHA .

Hope you will cooperate .

Yours

Tridib sir
dated 28th September 2018

## Science & Physics

Science, as we know, is built up with facts as a house is with bricks. But a collection of facts is no more a science than a pile of bricks is a house. Physics is the science of matter, energy, time, and space. Physics is an experimental science believing in the theories, proved by observations.

Physics, today, is a broad and highly developed subject and the research related to Physics is divided into many fields, for example: mechanics, electricity, heat, sound, light, condensed matter, atomic physics, nuclear physics, and elementary particle physics. A solid footing in physics will always prepare you to be a leader in our increasingly technical world.

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Physics is basically divided into four sub-categories: Condensed Matter Physics; Atomic, Molecular, and Optical Physics; High-energy Physics; and Astronomy and Astrophysics.

Most physicists also specialize in either theoretical or experimental research, the former dealing with the development of new theories, and the latter dealing with the experimental testing of theories and the discovery of new phenomena and thus giving us important discoveries during the last four centuries and the good works still going on ….

Physics is an exciting & thought provoking subject which can constantly open new vistas for knowing about our world and Universe. Studying physics can provide you with a flexible foundation to support careers and help solve problems in diverse fields. Therefore, it is very important that as a student of physics one must be very clear in understanding the fundamentals and principles of physics. With this thought we have created this site to fill the doubts of your mind. Best of Luck!!!