Explanation

The orbital speed (v) of a satellite is given by:

v = √(GM / (R + h))

If the orbital radius (R + h) is halved:

v' = √(GM / ((R + h) / 2))

= √(2GM / (R + h))

= √2 * √(GM / (R + h))

= √2 * v

So, the orbital speed will increase √2 times.

Explanation

Given:

Magnification M = 5

Distance between lenses L = f₀ + fₑ = 24 cm

Magnification formula M = f₀ / fₑ

Let's solve for f₀ and fₑ:

1. f₀ / fₑ = 5 => f₀ = 5fₑ

2. f₀ + fₑ = 24

Substituting f₀ = 5fₑ into the second equation:

5fₑ + fₑ = 24

6fₑ = 24

fₑ = 4 cm

Now, f₀ = 5fₑ = 5 × 4 = 20 cm

Explanation

The total time of flight (T) for a projectile is given by:

T = 2v₀sin(θ) / g

The maximum height (H) is:

H = (v₀sin(θ))² / (2g)

Using T = 2v₀sin(θ) / g, we can express v₀sin(θ) = gT/2. Substituting this into the height equation gives:

H = (gT/2)² / (2g) = g²T² / 8g = gT² / 8

Explanation

Surprised and Astonished are synonyms — both mean being amazed.

Likewise, Generosity and Magnanimity are synonyms — both mean kindness and nobility of spirit.

Explanation

The sentence is in the past tense, so the correct verb form is "spoke".

"Spoke" is the simple past tense of "speak," matching the context.

Explanation

True or False is a selection-type question where students choose between given options.

It does not require constructing an answer, just selecting the correct one.

Explanation

A function is concave down on an interval if its second derivative is negative over that interval.

Graphically, this means the curve bends downward like an upside-down bowl.

Explanation

عرش کا مطلب ہے اونچا مقام یا آسمانی تخت، جب کہ فرش نیچے کی سطح کو کہتے ہیں۔

اس لیے عرش اور فرش ایک دوسرے کے ضد (متضاد) ہیں۔

Explanation

Explanation

A dull black surface absorbs maximum radiation because it doesn’t reflect or transmit light.

Such surfaces are used in experiments and devices like blackbody radiators for accurate heat absorption.