Explore topic-wise InterviewSolutions in .

This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.

10051.

Choose the correct answer:Ran a Udai Singh/Jai Mal/Rana Pratap Singh was defeated by the Mughal forces in the Battle of Haldighati.

Answer»

Rana Pratap Singh was defeated by the Mughal forces in the Battle of Haldighati.

10052.

The picture depicts a Mughal emperor holding discussions on religious matters in the Ibadat Khana.Which religious communities participated in the discussions?

Answer»

Muslim clerics, Hindu scholars, Buddhist and Jain monks, Parsi priests, Christian missionaries, etc. assembled in the Ibadat Khanna.

10053.

When and for what purpose did Akbar built the Ibadat Khana?

Answer»

The Ibadat Khana was built in 1575 at Fatehpur Sikri. At this hall, he used to call selected theologians of all religions, mystics and intellectuals and discuss religious and spiritual matters with them.

10054.

Choose the correct answer:In 1575 ce, Akbar built the Ibadat Khana in his new capital for discussions on politics/religious/warfare.

Answer»

In 1575 ce, Akbar built the Ibadat Khana in his new capital for discussions on religious.

10055.

The symbol of family planning in India is: (a) Square (b) Inverted red triangle (c) Rectangle (d) Circle

Answer»

(b) Inverted red triangle

10056.

By What numbers should each of the following be divided to get a perfect square in each case? Also, find the number whose square is the new number. (i) 16562 (ii) 3698 (iii) 5103 (iv) 3174 (v) 1575

Answer»

(i) 16562 

16562 = (7 × 7) × (13 × 13) × 2 

\(\frac{16562}{2}\)= (7 × 7) × (13 × 13) 

\(\frac{16562}{2}\)= (7 × 13) × (7 × 13) = 91 × 91 

= 912 

Therefore, the resultant is the square of 91.

ii) 3698 

3698 = 2 × (43 × 43) 

\(\frac{3698}{2}\)= 43 × 43 

= 432 

Therefore, the numbers must be divided by 2 and resultant is square of 43.

(iii) 5103 

5103 = (3 × 3) × (3 × 3) × (3 × 3) × 7 

\(\frac{5103}{7}\)= (3 × 3 × 3) × (3 × 3 × 3) 

= 27 × 27 

= 272 

Therefore, the number must be divided by 7 and resultant is square of 27.

(iv) 3174 

3174 = 2 × 3 × (23 × 23) 

\(\frac{3174}{6}\)= 23 × 23 

= 232 

Therefore, the number must be divided by 6 and the resultant is square of 23.

(v) 1575

1575 = 3 × 3 × 5 × 5 × 7

\(\frac{1575}{7}\) = 3 × 3 × 5 × 5

= 15 × 15 

= 152 

Therefore, the number must be divided by 7 and the resultant is square of 15.

10057.

Evaluate:78 X 82

Answer»

Given 78 X 82

We can write 78 as 80-2 and also 82 as 80+2

We know that (a + b) X (a – b) = a2– b2

Here a= 80 and b = 2

Applying the above formula we get

(80 + 2) X (80 – 2) 

= (80)– (2)2

= 6400 – 4

= 6396

10058.

Write (T) for true and (F) for false for each of the statements given below:(i) The number of digits in a perfect square is even.(ii) The square of a prime number is prime.(iii) The sum of two perfect squares is a perfect squares.(iv) The difference of two perfect squares is a perfect square.(v) The product of two perfect squares is a perfect squares.

Answer»

(i) False

Explanation: Because the number of digits present in perfect square also be odd.

(ii) False

Explanation: A prime number is one that is not divisible by any other, except by 1 and itself. So square of a prime number is not always prime.

(iii) False

Explanation: The sum of two perfect square can be any number.

(iv) False

Explanation: The difference of two perfect square can be any number.

(v) True

Explanation: According to the properties of perfect square we have,

The product of two perfect squares is a perfect square.

10059.

By what number should each of the following numbers by multiplied to get a perfect square in each case? Also find the number whose square is the new number.(i) 8820(ii) 3675(iii) 605(iv) 2880(v) 4056(vi) 3468(vii) 7776

Answer»

(i) 8820 

8820 = (2 × 2) × (3 × 3) × (7 × 7) × 5 

In the above factors only 5 is unpaired 

So, multiply the number with 5 to make it paired 

Again, 

8820 × 5 = 2 × 2 × 3 × 3 × 7 × 7 × 5 × 5 

= (2 × 2) × (3 × 3) × (7 × 7) (5 × 5) 

= (2 × 3 × 7 × 5) × (2 × 3 × 7 × 5) = 210 × 210 

= (210)2 

So, the product is the square of 210 

(ii) 3675 

3675 = (5 × 5) × (7 × 7) × 3 

In the above factors only 3 is unpaired 

So, multiply the number with 3 to make it paired

Again, 

3675 × 3 = 5 × 5 × 7 × 7 × 3 × 3 

= (5 × 5) × (7 × 7) × (3 × 3) 

= (3 × 5 × 7) × (3 × 5 × 7) 

= 105 × 105 

= (105)2 

So, the product is the square of 105 

(iii) 605 

605 = 5 × (11 × 11) 

In the above factors only 5 is unpaired 

So, multiply the number with 5 to make it paired

Again, 

605 × 5 = 5 × 5 × 11 × 11 

= (5 × 5) × (11 × 11) 

= (5 × 11) × (5 × 11) 

= 55 × 55 

= (55)2 

So, the product is the square of 55 

(iv) 2880 

2880 = 5 × (3 × 3) × (2 × 2) × (2 × 2) × (2 × 2) 

In the above factors only 5 is unpaired 

So, multiply the number with 5 to make it paired 

Again, 2880 × 5 = 2 × 2 × 2 × 2 × 2 × 2 × 3 × 3 × 5 × 5

= (2 × 2) × (2 × 2) × (2 × 2) (3 × 3) × (5 × 5) 

= (2 × 2 × 2 × 3 × 5) × (2 × 2 × 2 × 3 × 5) 

= 120 × 120 

= (120)2 

So, the product is the square of 120 

(v) 4056 

4056 = (2 × 2) × (13 × 13) × 2 × 3 

In the above factors only 2 and 3 are unpaired 

So, multiply the number with 6 to make it paired 

Again, 4056 × 6 = 2 × 2 × 13 × 13 × 2 × 2 × 3 × 3 

= (2 × 2) × (13 × 13) × (2 × 2) (3 × 3) 

= (2 × 2 × 3 × 13) × (2 × 2 × 3 × 13) 

= 156 × 156

 = (156)2 

So, the product is the square of 156 

(vi) 3468 

3468 = (2 × 2) × 3 × (17 × 17) 

In the above factors only 3 are unpaired 

So, multiply the number with 3 to make it paired 

3468 × 3 = (2 × 2) × (3 × 3) × (17 × 17) 

= (2 × 3 × 17) × (2 × 3 × 17) 

= 102 × 102 

= (102)2 

So, the product is the square of 102 

(vii) 7776 

7776 = (2 × 2) × (2 × 2) × (3 × 3) × (3 × 3) × 2 × 3 

In the above factors only 2 and 3 are unpaired 

So, multiply the number with 6 to make it paired 

Again, 

7776 × 6 = 2 × 2 × 2 × 2 × 2 × 2 × 3 × 3 × 3 × 3 × 3 × 3 

= (2 × 2) × (2 × 2) × (2 × 2) (3 × 3) × (3 × 3) × (3 × 3) 

= (2 × 2 × 2 × 3 × 3 × 3) × (2 × 2 × 2 × 3 × 3 × 3) 

= 216 × 216 

= (216)2 

So, the product is the square of 216.

10060.

Fill in the blanks:(i) The square of an even number is……….(ii) The square of an odd number is…………(iii) The square of a proper fraction is………. than the given fraction.(iv) n2 = the sum of first n ……… natural numbers.

Answer»

Even 

Explanation: According to the property of perfect square i.e. the square of an Even number is always even.

Odd 

Explanation: According to the property of perfect square i.e. the square of an odd number is always odd.

Smaller

Explanation: According to the property of perfect square i.e. the square of a proper fraction is smaller than the fraction.

Odd

Explanation: According to the property of perfect square i.e. for ever natural number n, we have sum of first n odd natural numbers = n2

10061.

By what least number should the given number be multiplied to get a perfect square number? In each case, find the number whose square is the new number.(i) 3675(ii) 2156(iii) 3332(iv) 2925

Answer»

(i) Given 3675 Resolve 3675 into prime factors, we get 3675 = 3 X 5 X 5 X 7 X 7 Now to get perfect square we have to multiply the above equation by 3

Then we get, 3675 = 3 X 3 X 5 X 5 X 7 X 7

= (3 X 5X 72)

New number = (9 X 25 X 49)

= (3X 5X 72)

Taking squares as common from the above equation we get

∴ New number = (3 X 5 X 7)2

= (105)2

Hence, the new number is square of 105

(ii) Given 2156 Resolve 2156 into prime factors, we get 2156 = 2 X 2 X 7 X 7 X 11 = (2X 7X 11) Now to get perfect square we have to multiply the above equation by 11

Then we get, 2156 = 2 X 2 X 7 X 7 X 11 X 11

New number = (4 X 49 X 121)

= (2X 7X 112)

Taking squares as common from the above equation we get

∴ New number = (2 X 7 X 11)2

= (154)2

Hence, the new number is square of 154

(iii) Given 3332 Resolve 3332 into prime factors, we get 3332 = 2 X 2 X 7 X 7 X 17= (2X 7X 17) Now to get perfect square we have to multiply the above equation by 17

Then we get, 3332 = 2 X 2 X 7 X 7 X 17 X 17

New number = (4 X 49 X 289)

= (2X 7X 172)

Taking squares as common from the above equation we get

∴ New number = (2 X 7 X 17)2

= (238)2

Hence, the new number is square of 238

(iv) Given 2925 Resolve 2925 into prime factors, we get 2925 = 3 X 3 X 5 X 5 X 13= (3X 5X 13)Now to get perfect square we have to multiply the above equation by 13

Then we get, 2156 = 3 X 3 X 5 X 5 X 13 X 13

New number = (9 X 25 X 169)

= (3X 5X 132)

Taking squares as common from the above equation we get

∴ New number = (3 X 5 X 13)2

= (195)2

Hence, the new number is square of 195

10062.

By what number should each of the following numbers by multiplied to get a perfect square in each case? Also find the number whose square is the new number.(i) 8820(ii) 3675(iii) 605(iv) 2880

Answer»

(i) 8820

The prime factors for 8820

=8820 = 2×2×3×3×7×7×5  (grouping the prime factors in equal pairs we get)

= (2×2) × (3×3) × (7×7) × 5

Here,prime factor 5 is left out. So, multiply by 5 we get,

= 8820 × 5 

 = (2×2) × (3×3) × (7×7) × (5×5)

= (2×3×7×5) × (2×3×7×5)

= 210 × 210

= (210)2

(ii) 3675

The prime factors for 3675

3675 = 5×5×7×7×3 (grouping the prime factors in equal pairs we get)

= (5×5) × (7×7) × 3

Here,prime factor 3 is left out.So, multiply by 3 we get,

 = 3675 × 3 

= (5×5) × (7×7) × (3×3)

= (5×7×3) × (5×7×3)

= 105 × 105

= (105)2

(iii) 605

The prime factors for 605

605 = 5×11×11 (grouping the prime factors in equal pairs we get)

= (11×11) × 5

Here, prime factor 5 is left out.So, multiply by 5 we get,

= 605 × 5 

= (11×11) × (5×5)

= (11×5) × (11×5)

= 55 × 55

= (55)2

(iv) 2880

The prime factors for 2880

2880 = 5×3×3×2×2×2×2×2×2 (grouping the prime factors in equal pairs we get)

= (3×3) × (2×2) × (2×2) × (2×2) × 5

Here, prime factor 5 is left out. So, multiply by 5 we get,

= 2880 × 5 

= (3×3) × (2×2) × (2×2) × (2×2) × (5×5)

= (3×2×2×2×5) × (3×2×2×2×5)

= 120 × 120

= (120)2

10063.

Which of the following numbers are perfect squares?11, 12, 16, 32, 36, 50, 64, 79, 81, 111, 121

Answer»

(i) 11 it is a prime number.So it is not a perfect square.

(ii) 12 is not a perfect square.

(iii) 16= (4)2 

\(\therefore\) 16 is a perfect square.

(iv) 32 is not a perfect square.

(v) 36= (6)2 

\(\therefore\) 36 is a perfect square.

(vi) 50 is not a perfect square.

(vii) 64= (8)2 

\(\therefore\) 64 is a perfect square.

(viii) 79 it is a prime number. So it is not a perfect square.

(ix) 81= (9)2 

\(\therefore\) 81 is a perfect square.

(x) 111 it is a prime number. So it is not a perfect square.

(xi) 121= (11)2 

\(\therefore\) 121 is a perfect square.

10064.

Find the smallest number by which 180 must be multiplied so that it becomes a perfect square. Also, find the square root of the perfect square so obtained.

Answer»

Given,

180 = (2 × 2) × (3 × 3) × 5

=22 × 32 × 5

To make the unpaired 5 into paired, multiply the number with 5

180 × 5 = 22 × 32 × 52

∴ Square root of √(180 × 5) = 2 × 3 × 5

= 30

10065.

Fill in the blanks: (i) The square of an even number is…. (ii) The square of an odd number is……. (iii) The square of a proper fraction is ………..than the given fraction. (iv) n2 = the sum of first n ……. natural numbers

Answer»

(i) The square of an even number is even 

(ii) The square of an odd number is odd 

(iii) The square of a proper fraction is smaller than the given fraction 

(iv) n2 = the sum of first n odd natural numbers

10066.

By what least number should the given number be multiplied to get a perfect square number? In each case, find the number whose square is the new number.(i) 3675 (ii) 2156 (iii) 3332 (iv) 2925

Answer»

(i) 3675 

At first, We’ll resolve the given number into prime factors: 

Hence, 

3675 = 3 × 25 × 49 

= 7 × 7 × 3 × 5 × 5 

= (5 × 7) × (5 × 7) × 3 

In the above factors only 3 is unpaired 

So, in order to get a perfect square the given number should be multiplied by 3 

Hence, 

The number whose perfect square is the new number is as following: 

= (5 × 7) × (5 × 7) × 3 × 3 

= (5 × 7 × 3) × (5 × 7 × 3) 

= (5 × 7 × 3)2 

= (105)2 

(ii) 2156 

At first, We’ll resolve the given number into prime factors: 

Hence, 

2156 = 4 × 11 × 49 

= 7 × 7 × 2 × 2 × 11 

= (2 × 7) × (2 × 7) × 11 

In the above factors only 11 is unpaired 

So, 

in order to get a perfect square the given number should be multiplied by 11 

Hence, 

The number whose perfect square is the new number is as following: 

= (2 × 7) × (2 × 7) × 11 × 11 

= (2 × 7 × 11) × (2 × 7 × 11) 

= (5 × 7 × 11)2 

= (154)2 

(iii) 3332 

At first, We’ll resolve the given number into prime factors: 

Hence, 

3332 = 4 × 17 × 49 

= 7 × 7 × 2 × 2 × 17 

= (2 × 7) × (2 × 7) × 17 

In the above factors only 17 is unpaired 

So, in order to get a perfect square the given number should be multiplied by 17 

Hence, 

The number whose perfect square is the new number is as following: 

= (2 × 7) × (2 × 7) × 17 × 17 

= (2 × 7 × 17) × (2 × 7 × 17) 

= (2 × 7 × 17)2 

= (238)2 

(iv) 2925 

At first, We’ll resolve the given number into prime factors: 

Hence, 

2925 = 9 × 25 × 13 

= 3 × 3 × 13 × 5 × 5 

= (5 × 3) × (5 × 3) × 13 

In the above factors only 13 is unpaired 

So, in order to get a perfect square the given number should be multiplied by 13 

Hence, 

The number whose perfect square is the new number is as following: 

= (5 × 3) × (5 × 3) × 13 × 13 

= (5 × 3 × 13) × (5 × 3 × 13) 

= (5 × 3 × 13)2 

= (195)2

10067.

Find the smallest number by which the given number must be multiplied so that the product is a perfect square:(i) 23805(ii) 12150(iii) 7688

Answer»

(i) 23805

The prime factors for 23805

23805 = 3×3×23×23×5  ( grouping the prime factors in equal pairs we get,)

= (3×3) × (23×23) × 5 

Here 5 is left out. So, multiply by 5 we get,

= 23805 × 5 

= (3×3) × (23×23) × (5×5)

= (3×5×23) × (3×5×23)

= 345 × 345

= (345)2

(ii) 12150

The prime factors for 12150

12150 = 2×2×2×2×3×3×5×5×2  (grouping the prime factors in equal pairs we get,)

= (2×2) × (2×2) × (3×3) × (5×5) × 2

Here, prime factor 2 is left out. So, multiply by 2 we get,

 = 12150 × 2 

= (2×2) × (2×2) × (3×3) × (5×5) × (2×2)

= (2×2×3×5×2) × (2×2×3×5×2)

= 120 × 120

= (120)2

(iii) 7688

The prime factors for 7688

7688 = 2×2×31×31×2 (grouping the prime factors in equal pairs we get,)

= (2×2) × (31×31) × 2

Here, prime factor 2 is left out. So, multiply by 2 we get,

= 7688 × 2 

= (2×2) × (31×31)× (2×2)

= (2×31×2) × (2×31×2)

= 124 × 124

= (124)2

10068.

Which of the following is the square of an odd number? A. 2116 B. 3844 C. 1369 D. 2500

Answer»

As we know that, 

Square of an odd number is always an odd number. 

Hence, 

1369 is the square of an odd number. 

Therefore, 

Option (C) is the correct option.

10069.

Show that each of the following numbers is a perfect square. Also find the number whose square is the given number in each case:(i) 1156(ii) 2025(iii) 14641

Answer»

(i) 1156

The prime factors for 1156

1156 = 2×2×17×17

= (2×2) × (17×17)  (none of the prime factors are left out..)

Hence, 1156 is a perfect square.

Now,

1156 = (2×17) × (2×17)

= 34 × 34

= (34)2

∴ 1156 is a square of 34

(ii) 2025

The prime factors for 2025

2025 = 3×3×3×3×5×5

= (3×3) × (3×3) × (5×5)  (none of the prime factors are left out..)

Hence, 2025 is a perfect square.

Now,

2025 = (3×3×5) × (3×3×5)

= 45 × 45

= (45)2

∴ 2025 is a square of 45.

(iii) 14641

 The prime factors for 14641

14641 = 11×11×11×11

= (11×11) × (11×11)  (none of the prime factors are left out..)

Hence, 14641 is a perfect square.

Now,

14641 = (11×11) × (11×11)

= 121 × 121

= (121)2

∴ 14641 is a square of 121.

10070.

Which of the following numbers is not a perfect square? (a) 3600 (b) 6400 (c) 81000 (d) 2500

Answer»

(c) 81000

Explanation:

According to the property of a square a number ends in an odd number of zeros is not a perfect square.

10071.

Which of the following numbers is not a perfect square? (a) 1156 (b) 4787 (c) 2704 (d) 3969

Answer»

(b) 4787

Explanation:

According to the property of square a number ending with 2, 3, 7 and 8 is not a perfect square.

10072.

A hall has a capacity of 2704 seats. If the number of rows is equal to the number of seats in each row, then find the number of seats in each row.

Answer»

From the question it is given that total number of seats = 2704

Let us assume number of seats in each row be ‘a’

As per the condition given in the question,

Number of rows is equal to the number of seats in each row i.e. ‘a’

Then,

Total number of seats = a × a

2704 = a2

By taking square root on both side,

a = √(2704)

a = √(52 × 52)

a = √(52)2

a = 52

∴The number of seats in each row is 52.

10073.

The number of trees in each row of a garden is equal to the total number of rows in the garden. After 111 trees have been uprooted in a storm, their remain 10914 trees in the garden. The number of rows of trees in the garden is (a) 100 (b) 105 (c) 115 (d) 125

Answer»

(b) 105

Let the number of rows = number of trees = x 

\(\therefore\) Total number of trees in the garden 

= x × x = x2 = 10914 + 111 = 11025 

\(\therefore\) No. of rows of trees = \(\sqrt{11025}\) = 105

10074.

1225 plants are to be planted in a garden in such a way that each row contains as many plants as the number of rows. Find the number of rows and the number of plants in each row.

Answer»

Let the number of rows be x

Therefore,

The number of plants in each row is also x

Hence,

Total number of plants = (x × x) = x2 = 1225

x2 = 1225 = 5 × 5 × 7 × 7

x = \(\sqrt{1225}\) = 5 × 7 = 35

Thus, 

The total number of rows is 35 and the number of plants in each row is also 35

10075.

Find the ratio of the shaded portion to the unshaded portion in Fig. 8.1

Answer»

Number of squares in the shaded portion = 15 Number of squares in the unshaded portion = 33 So, the ratio of the shaded portion to the unshaded portion = 15 : 33 = 15/33 = 5x3/11x3 = 5/11 = 5:11

10076.

Write the ratio of shaded portion to the unshaded portions in the following shapes.

Answer»

(i) Ratio = 1 : 2

(ii) Ratio = 5 : 4

10077.

In a school excursion, 6 teachers and 12 students from 6th standard and 9 teachers and 27 students from 7th standard, 4 teachers and 16 students from 8th standard took part. Which class has the least teacher to student ratio?

Answer»

Teacher to Student Ratio of 6th Std = 6 : 12 = 1 : 2

Teacher to Student Ratio of 7th Std = 9 : 27 = 1 : 3

Teacher to Student Ratio of 8th Std = 4 : 16 = 1 : 4

In standard 8th the ratio of teacher to student is 1 : 4 and which is the least.

10078.

Select the most appropriate answer the alternatives given below and rewrite the SentenceFurther capital introduced during the year is ________ from closing capital in order to find-out the correct profit.OptionsAddedDeductedDividedIgnored

Answer»

Further capital introduced during the year is deducted from closing capital in order to find out the correct profit.

Explanation: Under single-entry system, profit or loss is calculated by comparing capital at two dates, i.e. opening capital and closing capital (net worth method). The profit is calculated as closing capital less opening capital and also, the following adjustments are made:

a. Drawings: If drawings are made during the year, they should be added to the amount of closing capital.

b. Additional capital: If additional capital is introduced in the business during the year, it should be deducted from the amount of closing capital.

c. Interest on capital: If interest is provided on capital, it should be deducted from the amount of closing capital.

10079.

Fill in the Blank:i. Statement of Affairs is just like ______ii. Under Single Entry System, Profit = Closing Capital Less _______iii. In order to find out the correct profit, drawings are _______ to the closing capital.iv. In ________ Book Keeping System, in every business transactions we find two effects.v. The difference between Assets and Liabilities is called __________vi. Single Entry System is more popular for __________vii. Additional Capital introduced during the year is _____ from Closing Capital in order to find out the correct profit.viii. Single Entry System is Suitable for _____business.

Answer»

i. Balance Sheet

ii. Opening Capital

iii. Added

iv. Double Entry System

v. Capital

vi. Sole Trader

vii. Deducted

viii. Small

10080.

A statement of __________ is to be prepared in under to find out profit or loss under a single entry system. (a) Income (b) Affairs (c) Revenue (d) Profit or Loss

Answer»

Correct option is (d) Profit or Loss

10081.

Fill in the Blanks :(i) In statement of profit or loss, profit on sale of assets are _________ to closing capital.(ii) Bad debts are ___________ from closing capital in statement of profit or loss.(iii) __________ unscientific system of Bookkeeping.(iv) Under the Single Entry System, profit or loss is calculated by deducting the opening capital balance from __________ at the end of the year.

Answer»

(i) Added

(ii) Deducted

(iii) Single Entry System

(iv) the closing capital balance

10082.

Do you agree with the following statements?(i) The single Entry System of Book-keeping is a scientific method of books of accounts.(ii) The single Entry System is useful only for large organizations.(iii) Statement of Affairs is just like a profit and loss account.(iv) The difference between Assets and Liabilities is called net profit.(v) The single Entry System follows the golden rules of accounts.

Answer»

(i) Disagree

(ii) Disagree

(iii) Disagree

(iv) Disagree

(v) Disagree

10083.

Find the odd one :(i) Stock in trade, Bank overdraft, Bills receivable.(ii) Interest on Loan, Interest on Investment, Income receivable.(iii) Bad debts, Reserve for Bad debts, Reserve for a discount on creditors.(iv) Income received in advance, Prepaid Expenses, Outstanding Expenses.

Answer»

(i) Bank overdraft

(ii) Interest on Loan

(iii) Reserve for a discount on creditors

(iv) Prepaid Expenses

10084.

Fill in the Blanks :(i) In __________ Book-keeping system, only Cash/Bank A/c and Personal accounts of Debtors and Creditors are opened.(ii) Capital is the difference between _________ and _________(iii) Single Entry System of Book-keeping is ___________ system of books of accounts.(iv) ____________ accuracy is not guaranteed under Single Entry System.

Answer»

(i) Single Entry

(ii) Assets, Liabilities

(iii) Conventional Accounting

(iv) Arithmetical

10085.

If marked price = Rs 1700, selling price = Rs 1540, then find the discount.

Answer»

Here, Marked price = Rs 1700, selling price = Rs 1540 

Selling price = Marked price – Discount 

∴ 1540 = 1700 – Discount 

∴ Discount = 1700 – 1540 = Rs 160 

∴ The amount of discount is Rs 160.

10086.

How do these properties vary in period and group? 1) Valency 2) Atomic radius 3) Ionisation energy 4) Electron affinity 5) Electronegativity 6) Electro-positivity 7) Metallic nature 8) Non-Metallic nature.

Answer»
Periodic propertiesTrend in 
Group From tp to bottomPeriods From left to right
1. ValencySameDoes not follow trend
2.  Atomic radiusIncreasesDecreases
3. Ionisation energyDecreasesIncreases
4. Electron affinityDecreasesIncreases
5. Electronegativity DecreasesIncreases
6. ElectropositivityIncreasesDecreases
7. Metallic natureIncreasesDecreases
8. Non- metallic natureDecreasesIncreases
10087.

Which of the following properties of a nucleus does not depend on its mass number? (A) radius (B) mass (C) volume (D) density

Answer»

Correct option is (D) density

10088.

What is the amount of \(^{60}_{27}Co\) necessary to provide a radioactive source of strength 10.0 mCi, its half-life being 5.3 years?

Answer»

Data : Activity = 10.0 mCi = 10.0 × 10-3 Ci

= (10.0 × 10-3 )(3.7 × 1010) dis/s = 3.7 × 10dis/s

T1/2 = 5.3 years = (5.3)(3.156 × 107 ) s

= 1.673 × 108 s

Decay constant, \(\lambda\) = \(\cfrac{0.693}{T_{1/2}}\) = \(\cfrac{0.693}{1.673\times10^8}s-1\)

=4.142 × 10-9 s-1

Activity = Nλ

∴ N = \(\cfrac{activity}{\lambda}\) = \(\cfrac{3.7\times10^8}{4.142\times10^{-9}}\) atoms

= 8.933 × 1016 atoms 

= 60 grams of \(^{60}_{27}Co\) contain 6.02 × 1023 atoms

Mass of 8.933 × 1016 atoms of \(^{60}_{27}Co\)

\(\cfrac{8.933\times10^{16}}{6.02\times10^{23}}\) x 60 g

= 8.903 × 10-6 g = 8.903 µg 

This is the required amount.

10089.

If the number of nuclei in a radioactive sample at a given time is N, what will be the number at the end of two half-lives?(A) \(\frac{N}2\)(B) \(\frac{N}4\)(C) \(\frac{3N}4\)(D) \(\frac{N}8\)

Answer»

Correct option is  (B) \(\frac{N}4\)

10090.

What does the metaphor ‘the bottle of wine’ represent ? (a) body (b) spirit (c) soul (d) body and soul

Answer»

Correct answer is (a) body

10091.

Why does the author say, “The years drink up the wine, and at last throw the bottle away” ? लेखक यह क्यों कहता है, “समय शराब को पी जाता है और अन्त में बोतल फेंक देता है?

Answer»

The author says that people think soul, spirit or mind to be the essence of life. They compare the soul, spirit or mind with the wine and the body to its bottle. They see one’s death in the sense that time has consumed the essence of life and the bottle i.e. body is of no use now.

लेखक कहता है कि लोग आत्मा, भावना या सोच को जीवन का सार मानते हैं। वे आत्मा, भावना या सोच की तुलना शराब से करते हैं और शरीर की तुलना इसकी बोतल से। वे व्यक्ति की मृत्यु को इस रूप में देखते हैं कि समय ने जीवन के सार का उपभोग कर लिया है और अब बोतल अर्थात् शरीर व्यर्थ है।

10092.

Consider Fig.11.1 for photo emission. How would you reconcile with momentum-conservation? Note light (photons) have momentum in a different direction than the emitted electrons.

Answer»

The momentum is transferred to the metal. At the microscopic level, atoms absorb the photon and its momentum is transferred mainly to the nucleus and electrons. The excited electron is emitted. Conservation of momentum needs to be accounted for the momentum transferred to the nucleus and electrons.

10093.

If we consider electrons and photons of same wavelength then will have same (a) momentum (b) angular momentum (c) energy (d) velocity

Answer»

(a) momentum

As p = h/λ, so electrons and photons having the same wavelength λ will have the same momentum p.

10094.

Give mathematic expression for power lens and explain the terms in the formula.

Answer»

Power (P) = 1/f

where f is focal length of lens.

10095.

What will be the energy of each photon in monochromatic light of frequency 5 × 1014 Hz?

Answer»

Data: y = 5 × 1014 Hz, h = 6.63 × 10-34 Js,

1eV =1.6 × 10-19 J

The energy of each photon,

E = hv = (6.63 × 10-34 J.s)(5 × 1014 Hz)

= 3.315 × 10-19 J

\(\cfrac{3.315\times10^{-19}J}{1.6\times10^{-19}{\frac{j}{eV}}}\) = 2.072 eV

10096.

Write the lens maker’s formula and explain the terms in it. (OR) Ravi wants to make a lens. Which formula he has to follow ? Write the formula and explain the terms in it. (OR) Write lens formula.

Answer»

Lens maker’s formula:

1/f = (n - 1) (\(\frac {1}{R_1} - \frac {1}{R_2}\))

n = Refractive index of the medium 

R1 = Radius of curvature of 1 st surface 

R2 = Radius of curvature of 2nd surface 

f = Focal length

10097.

Write correct form of units in the following. (i) DB (ii) mhz (iii) 20 – m (iv) kg.m-s-2

Answer»

(i) dB 

(ii) MHz 

(iii) 20 m 

(iv) Kg.m.s-2

10098.

Photon of frequency u has a momentum associated with it. If c is the velocity of radiation, then the momentum is(a) \(\frac{hv}{c}\)(b) \(\frac{v}{c}\)(c) hυc(d) \(\frac{h}{c^2}\)

Answer»

(a) \(\frac{hv}{c}\)

p = \(\frac{E}{c^2} =\frac{hv}{c}\)

10099.

What is the energy of a photon (quantum of radiation) of frequency 6 × 1014 Hz? [h = 6.63 × 10-34 J∙s]

Answer»

hv = (6.63 × 10-34)(6 × 1014)

= 3.978 × 10-19 J is the energy of the photon.

10100.

Find the energy of a photon if (i) the frequency of radiation is 100 MHz (ii) the wavelength of radiation is 10000 Å.(h = 6.63 × 10-34 J∙s, c = 3 × 108 m/s, e = 1.6 × 10-19 J, m (electron) = 9.1 × 10-31 kg)

Answer»

Data : h = 6.63 × 10-34 J∙s, 

v = 100 MHz = 100 × 106 Hz, 

λ = 10000 Å = 106 m, 

c = 3 × 108 m/s

(i) The energy of a photon, E = hv

= (6.63 × 10-34)(100 × 106 ) = 6.63 × 10-26J

(ii) The energy of a photon, E = \(\cfrac{hc}λ\)

\(\cfrac{(6.63\times10^{-34})(3\times10^8)}{10^{-6}}\) = 1.989 × 10-19 J