Machine

Q.

Define load and effort.

Q.

What are the advantages of using simple machine?

Q.

Why is a machine not 100% efficient?

Q.

What is the use of input unit

Q.

What do you understand by an ideal machine ? How does it differ from a pratical machine ?

Q.

State four ways in which machines are useful to us.

Q.

(a) What do you understand by a simple machine ?

(b) State the principle of an ideal machine.

Q.

What is the relation between load and the effort while calculating the reciprocal of Mechanical Advantage?.

1. $\frac{Load}{Effort}$

2. $\frac{Effort}{Load}$

3. $\frac{Effort+Load}{Load}$

4. $\frac{Effort}{Effort+Load}$

Q.

A lever can act as a force multiplier and speed multiplier simultaneously.

1. True

2. False

Q.

A certain machine is very efficient.

What does this mean?

1. It produces a large amount of power.
2. 
   

   It uses very little energy.

3. 
   

   It wastes very little energy.

4. 
   

   It works very quickly.

Q.

What is the single movable pulley ? What is its mechanical advantage in the ideal case ?

Q. A walnut can be broken by applying a direct force of $60\text{kgf}$. If the walnut is placed in a nutcracker, the length of whose handle is $15\text{cm}$, and the nut is placed $2\text{cm}$ from the pivot, calculate the minimum force required to crack the nut.

Q.

Give four reasons for using machines.

Q.

Identify A Company That Offers Of-enabled Controllers.

Q.

A single fixed pulley makes the task easier by changing the direction of the effort.

1. True
2. False

Q.

Why do you need less effort to drive in a screw through a piece of wood rather than to hammer in a nail?

Q.

Name the simple machine used for cutting cloth.

Q. Which of the following statements supports the non-existence of an ideal machine?

1. Moving parts are not frictionless.
2. String is not perfectly elastic.
3. Different parts are not perfectly rigid.
4. All the input work is converted to output work.

Q. The direction or the magnitude of an effort can be changed by a machine.

1. True
2. False

Q.

A class I lever acts as a force multiplier.

1. True
2. False

Q. Name a machine which is used to change the direction of effort in a convenient direction.

1. Single fixed pulley
2. Wheel
3. Wedge
4. Single movable Pulley

Q. What is an inclined plane? What is its use ? Give two examples where it is used.

Q.

In a simple machine, if the effort arm is doubled and the load arm is halved, then how does the velocity ratio (VR) change?

1. Becomes half of the initial value.

2. Remains the same.

3. Becomes 2 times the initial value.

4. Becomes 4 times the initial value.

Q.

In which of the following ways does the machine help us?

1. Both A and C

2. Loss in speed.

3. In lifting heavy load by using less effort.

4. Changing the direction of effort.

Q.

"An ideal machine cannot be made practically." Justify the statement.

Q.

List the daily life situations where you use simple machines.

Place: In Kitchen

Situation:

Simple Machine:

Q. A machine is termed as force multiplier, if the effort required is

1. 0
2. > load
3. < load
4. = load

Q.

What is a simple machine?

Q.

In a gear system, the gear ratio of the driving wheel A and driven wheel B is 10$:$ 1. To rotate the driven wheel B in the direction of driving wheel A, the driving wheel A is engaged with another wheel C. What should be the gear ratio of the wheels A and C?

1. 1: 10

2. 1: 1

3. 1: 2

4. 2: 1

Q.

Where Is PERT Used?