Question

Answers please. Explain.
1. Keeping the object stationary, if the plane mirror is shifted through 6 cm towards
the object, the shift in the image is: (a) 6 cm towards the object; (b) 2 cm away;
(c) 12 cm towards; (d) 4 cm away from the object.

2. Time period of a simple pendulum depends upon- (i)Mass of bob;
(ii) Length of pendulum; (iii) Both; (iv) None.

3. A pendulum has angles as 60.15 degrees, 75 degrees, 108.1 degrees,
177 degrees. Then the 5th angle is ___.

4. Plants such as Rhizophora which grow in marshy areas have secondary roots
coming out of the soil, which help in respiration. They are called:
a- Stilt roots
b- Prop roots
c- Thorns
d- Pneumatophores.

5. Which of the following states of matter has/have a definite shape, but not
definite volume? Solid, Liquid, Gas.

6. A girl of a height 2-m is standing in front of a plane mirror of height 6-m. She is
standing 12-m away from the mirror, if she moves 8-m towards the mirror. What
will be the height of the image of the girl (in metre)?

Answer 1

1 .C) is the answer....
2.c)

Answer 2

Answer:

Correct answers are 1. $6$ $cm$,  2. pendulum's length,  3. $119.75^{0}$, 4. pneumatophores,  5. liquid,  and  6. $2m$

Explanation:

• The virtual image's distance behind the plane mirror is equal to the object's distance in front of the mirror.
• Gas, solid, and liquid are the three states of matter.
• The virtual image's height formed by a plane mirror is equal to the height of the real object

Solution 1:

1.   As, the virtual image distance and object distance will remain the same. So, the image will shift $6$ $cm$ towards the object. Option (a) is correct.

Solution 2:

2.   Formula for the pendulum's time period is:

$T=2\pi \sqrt{\frac{L}{g} }$

So, the time period depends on the pendulum's length.

Option (ii) is correct.

Solution 3:

3.   The $5th$ angle is $=540^{0} -60.15^{0} -75^{0} -108.1^{0} -177^{0}$

                                $=119.75^{0}$

Solution 4:

4.   In some plants such as Rhizophora that grow in wetlands, many roots grow out of the ground and grow upwards. Such roots are called pneumatophores.

Option d- is correct.

Solution 5:

5.   The correct answer is liquid.

Solution 6:

6.   The height of the image of the girl will remain the same $2$ $m$.