Hello everybody,

It’s Sunday 🙂 and time for our Weekly Exams Questions with Solution.

*Every week from Monday to Thursday, we post questions (Biology, Chemistry, Physics and Mathematics) on our social media learning platforms for the preparation of several examinations like JEE Main, JEE Advanced, BITSAT, AIPMT, AIIMS, State PMT, KVPY, NTSE, Olympiads.*

**For those who are not connected with Mystudycart on Social media:** In-case you want real time experience of answering questions and clearing doubts, then be a part of our social media learning pages on Facebook or Google+.

(Update : From 2016, we are no longer posting regular questions on social platforms.)

Questions and answers from this week,

### Biology Questions (Posted on Monday, November 02, 2015)

**Q 1.** Among bitter gourd, mustard, brinjal, pumpkin, china rose, lupin, cucumber, sunnhemp, gram, guava, bean, chilli, plum, petunia, tomato, rose, withania, potato, onion, aloe and tulip how many plants have hypogynous flower? **[For AIPMT Preparation]**

a) Six

b) Ten

c) Fifteen

d) Eighteen

**Answer:** c) Fifteen

These plants have hypogynous flower – mustard, brinjal, china rose, lupin, sunhemp, gram, bean, chilli, petunia, tomato, withania, potato, onion, aloe and tulip.

**Q 2. **A lake with an inflow of domestic sewage rich in organic waste may result in: **[For AIIMS Preparation]**

a) Drying of the lake very soon due to algal bloom

b) An increased production of fish due to lot of nutrients

c) Death of fish due to lack of oxygen

d) Increased population of aquatic food web organisms

**Answer: **c) Death of fish due to lack of oxygen

### Chemistry Questions (Posted on Tuesday, November 03, 2015)

**Q 1.** Isotopes of an element have : **[For NTSE Chemistry]**

a) Same Physical Properties

b) Different Chemical Properties

c) Different No. of Neutrons

d) Different Atomic Number

**Answer: **c) Different No. of Neutrons.

Isotopes have same number of proton but different no of neutrons.

**Q 2.** Of more than 114 elements known so far, …….. are metals : **[For NTSE Preparation]**

a) 74

b) 64

c) 94

d) 84

**Answer: **d) 84

There are 84 metal elements on the Periodic Table of Elements, four of which are unnamed at this time.

### Physics Questions (Posted on Wednesday, November 04, 2015)

**Q 1.** A Parachutist of weight W strikes the ground with his legs fixed and come to rest with an upward acceleration of magnitude 3g. Force exerted on him by the ground during landing is **[For NTSE Preparation]**

1) W

2) 2W

3) 3W

4) None of the above

**Answer: **4) None of the above

Mg = W

N -W = 3mg

N – W = 3W

N = 4W

**Q 2.** What is the power of a concave lens whose focal length is –75.0 cm ? **[For NTSE SAT Preparation]**

a) 1.33 D

b) –13.3 D

c) 13.3 D

d) –1.33 D

**Answer: **d) -1.33 D

P = 100/-75 = -1.33D

### Mathematics Questions (Posted on Thursday, November 05, 2015)

**Q 1.** In a right angled triangle ABC, right angled at B, if tan A = 1, then the value of 2 sin A cos A : **[NTSE Mathematics]**

a) 2

b) 1

c) – 1

d) 0

**Answer: **b) 1

**Q 2.** If the radius of a circle is a rational number, its area is given by a number which is : **[NTSE Stage1 Mathematics]**

a) Irrational

b) Rational

c) Integral

d) A perfect square

**Answer: **a) Irrational.

The value of Pi is irrational, so the product of rational and irrational is irrational.

### Bonus Mathematics Puzzle (Posted on November 05, 2015)

*A 50 cent coin has 12 equal sides. If you place two coins next to each other on a table (see diagram), what is the angle θ formed between the two coins?*

This was asked to 12th grade (age 17 and 18) students in Australia.

**Solution:**

**Method 1:** Imagine a third coin which leaves a gap of an equilateral triangle between the three coins. In an equilateral triangle all the angles are equal to 60 degrees, so X is 60 degree.

**Method 2:** In a 12-gon (dodecagon), a single exterior angle is 1/12 of 360, which is 30 degrees. Thus angle X is twice that, or 60 degrees.

Here is the video solution of this question:

So, that’s it from this week.

I will see you next Sunday with a new set of questions.

Thanks so much. Take care.