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(a) 1 N; vertically downward

Mass of the stone, m = 0.1 kg

Acceleration of the stone, a = g = 10 m/s² 

As per Newton’s second law of motion, the net force acting on the stone, 

F = ma = mg 

= 0.1 × 10 = 1 N

Acceleration due to gravity always acts in the downward direction.

(b) 1 N; vertically downward 

The train is moving with a constant velocity. Hence, its acceleration is zero in the direction of its motion, i.e., in the horizontal direction. Hence, no force is acting on the stone in the horizontal direction.

(c)1 N; vertically downward 

It is given that the train is accelerating at the rate of 1 m/s² 

Therefore, the net force acting on the stone, F' = ma = 0.1 × 1 = 0.1 N

This force is acting in the horizontal direction. Now, when the stone is dropped, the horizontal force F,' stops acting on the stone. This is because of the fact that the force acting on a body at an instant depends on the situation at that instant and not on earlier situations.

Therefore, the net force acting on the stone is given only by acceleration due to gravity. 

F = mg = 1 N

This force acts vertically downward.

(d) 0.1 N; in the direction of motion of the train

The weight of the stone is balanced by the normal reaction of the floor. The only acceleration is provided by the horizontal motion of the train.

Acceleration of the train, a = 0.1 m/s² 

The net force acting on the stone will be in the direction of motion of the train. Its magnitude is given by: 

F = ma

= 0.1 × 1 = 0.1 N

Correct Option  (c) Parabolic path 

Explanation:

Due to constant velocity along horizontal and vertical downward force of gravity stone will hit the ground following parabolic path

Relative velocity is the phenomenon responsible for such a motion.

x ∝ t³ or x = kt³.

or, v = dx/dt = 3kt².

For acceleration,a = dv/dt = 3k(2t) = 6kt

⇒ a = 6kt ⇒ a ∝ t.

The acceleration is directly proportional to the time.

x ∝ t² = kt² where k is a constant

a = ((d/dt)(dx/dt)) = (d/dt) (2 k t )

= 2 k

∴ Acceleration is constant/uniform.

If x ∝ t³ where k is a constant

a = ((d/dt)(dx/dt)) = (d/dt)(3 k t²) = 6 k t

∴ Acceleration is non-uniform

(a) One dimensional motion

(b) Two-dimensional motion

(c) Three-dimensional motion

(d) Three-dimensional motion.

It is moving with constant acceleration.

Acceleration of stone w.r.t. passenger = \(\sqrt{a^2+g^2}\)

Work is done whenever the given two conditions are satisfied:

(i) A force acts on the body.

(ii) There is a displacement of the body by the application of force in or opposite to the direction of force.

If the direction of force is perpendicular to displacement, then the work done is zero.

When a satellite moves around the Earth, then the direction of force of gravity on the satellite is perpendicular to its displacement. Hence, the work done on the satellite by the Earth is zero.

• When the artificial satellite moves around the earth in a circular orbit, gravitation force acts on it.
• The gravitational force acting on the satellite and its displacement are perpendicular to each other. i.e. 0 = 90°
• For 0 = 90°, work done is zero. [ v cos 90 = 0)
• Hence, work done on an artificial satellite by gravity is zero while moving around the earth.

• Wind has certain energy. 
• When it hits the windmill energy is transferred to the windmill because of which it moves. 
• Hence, wind can move the blades of a wind mill.

• The exploding firecracker converts the chemical energy stored in it into light and sound respectively. 
• Here, energy is converted from one type to another. 
• Hence, an exploding firecracker lights as well as makes a sound.

C) Wheat-Andhra Pradesh

C) 1 & 2 are true

Given,

Dimension of room = 12.5m × 9m × 7m

Dimension of door = 2.5m × 1.2m

Dimension of window = 1.5m × 1m

So, area of room = 2(l + b)h = 2(12.5 + 9)×7 = 301 m²

Area of 2 doors = 2(2.5 × 1.2) = 6m²

Area of 4 windows = 4(1.5 × 1) = 6 m²

So, area to be painted = (301 - 12) = 289 m²

∴ cost of painting walls at rate Rs.3.50 per m² = 3.50 × 289 = Rs.1011.50

C) Both A and B

Given details are,

Dimensions of class room = 11m × 8m × 5m

Where, Length = 11m, Breadth = 8m, Height = 5m

We know,

Area of floor = length × breadth

= 11 × 8

= 88 m²

Area of four walls (including doors & windows) = 2 (lh + bh) cm²

= 2 (11×5 + 8×5)

= 2 (55 + 40)

= 2 (95)

= 190m²

∴ Sum of areas of floor and four walls = area of floor + area of four walls

= 88 + 190

= 278 m²

Organic Material: The material obtained from degrading all the biological waste in the compost pit can be termed as organic material.

It is also known as Secondary Storage or Auxiliary Memory. It is slower and cheaper form of memory, which is a permanent storage device. CPU does not access the secondary memory directly. The contents in it must be first copied into the RAM to get processed. 

It is non-volatile in nature, i.e. the information does not get erased even power gets switched OFF and data will not be destructed until and unless, the user erases it. 

Secondary memory devices include 

(a)  Magnetic disks 

1. Floppy Disk  

2. Hard Disk Drive 

3. Magnetic Tape 

(b)  Optical discs 

1. CD 

2. DVD 

3. Blu-ray Disc 

(c) Solid State 

1.  Pen/Flash Drive

2.  Memory Card

Magnetic tape is an example of secondary memory.

3. ASP and 

4. PHP are not client side scripts.

Client Side :

1. JAVASCRIPT

2. VBSCRIPT Server Side

3. ASP

4. JSP

(c) Active server pages

The primary memory is volatile and has limited storage capacity, whereas secondary memory is non-volatile and can store huge amount of data.

RAM because it has above given features.

False 

The secondary or magnetic memory is a non-volatile memory.

False 

Random Access Memory (RAM) is a volatile memory, if current is interrupted, data will lost.

Server side scripting

1. ASP

2. JSP Client side scripting

3. Javascript

4. VBscript Vi

Computer memory is divided into primary  and secondary memory.

(b) Nerve centre because it controls the overall processing of a computer system.

One need an authorized license paid in order to use this proprietary software while open source software can be used by anybody and are usually free. One can use this software for their personal use. After giving any notation or code in this type one cannot change the code or modify it.

Ravi could either of the two technologies Bluetooth or Infrared which is supported by both the devices involved. Infrared though slightly faster than Bluetooth has a limitation that it needs a clear line-of-sight between the devices for it to work.

MODEM performs the task of Modulation at sender’s site and DEModulation at the receiver’s end. Basically, our computer generates data in the form of digital signals which needs to be forwarded to the receiver through telephone lines. Since, telephone lines can carry only analog signals. So digital signals need to be converted to analog signals at sender’s site this is called modulation. At receiver’s end again analog signals should be converted back to the original digital signals, then this is called demodulation.

1. MS-Office – All office applications MS-Word, MS-Excel, MS-PowerPoint.

2. Visual Studio – Visual Basic, Visual C+ + software for application development.

Multimedia Messaging Service (MMS)

(i) computers 

(ii) connected

(iii) communication 

(iv) network 

(v) share

No, because only a meaningful exchange of information between two living beings is called communication.

Communication channel for telephone line is twisted pair cable and for TV is co-axial cable.

Differences between LAN, MAN and WAN

Two major points of differences among LAN, MAN and WAN are as follows: 

1. Distance Covered LAN can cover an area upto 5 km. More than 5 km and upto 100 km comes under MAN. Beyond 100 km, the area can be covered by WAN only. 

2. Cost LAN has lower cost as compared to MAN and WAN.

LAN 

A Local Area Network (LAN) is a computer network covering a small geographical area like a home, office or small group of buildings such as buildings in a school. Computers connected to a LAN can share information and share peripheral equipments. 

WAN

A Wide Area Network (WAN) is used to connect LANs and other types of network together, so that users and computers in one location can communicate with users and computers in other locations.

(i) Computer memory enables a person to retain the information that is stored on the computer. 

(ii) Computer has basically two types of memory as follows: 

Internal memory Main memory units (RAM and ROM) and cache memory. External memory Secondary memory.

(d) LANs are not public network and hence data can be shared among the computers of the organisation owning that LAN cannot share data across the world.

1. Components of network are as follows: 

(a) Sender 

(b) Communication channel 

(c) Receiver 

2. Communication channel is the channel in which two computers can communicate with each other by sending data or sharing information between them.

Bluetooth technology is used for sharing the data like audio, video etc. Using this technology, users of cellular phones, initiate the sending or receiving data. In general, having all mobiles and fixed computer devices can be totally coordinated. Thus, Mr. Singh and Mr. Tyagi can send a song to each other by using a bluetooth technology easily within short time.

1. Kernels

2. Unix

3. Linux

(b) Across the continents, computers can be connected using WAN only.

(d) Computer connected with LAN can share information or peripheral devices.

1. Monitors the performance of the system, enables software to communicate with hardware and application softwares to be loaded; gives prompts and error reports to the users. 

 2. Antivirus and compression tool.

Manoj would be setting up a PAN (Personal Area Network) which is best suited for setups involving a computer, a cell phone and/or a handheld computing device such as a PDA.