Top-20 RRB NTPC Clock Based Questions

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Top 20 RRB NTPC Clock Based Questions
Top-20 RRB NTPC Clock Based Questions

RRB NTPC Clock Based Questions

Download Top-20 Clock Based questions for RRB NTPC  exam. Most important  Clock Based  questions based on asked questions in previous exam papers for RRB NTPC.

Download Top-20 RRB NTPC Clock Based Questions

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Question 1: Find the angle between the hour hand and the minute hand of a clock when the time is 10.25 hours i.e. 25 minutes past 10 ?

a) 180°

b) 165°

c) $162\frac{1}{2}°$

d) $152\frac{1}{2}°$

Question 2: Three bells ring at intervals of 15, 20 and 30 minutes respectively. If they all ring at 11.00 a.m. together, at what lime will ‘ they next ring together?

a) 11.30 a.m.

b) 12 noon

c) 12.30 p.m.

d) 1.00 p.m.

Question 3: At a telephone exchange, three phones ring at intervals of 20 sec, 24 sec and 30 seconds. If they ring together at 11:25 a.m, when will they next ring together?

a) 11:29 a.m.

b) 11:27 am.

c) 11:51 a.m.

d) 12:29 p.m.

Question 4: A clock shows 2 am now Find the total rotation of the minute hand, in degrees, of the clock when it will show 9 pm on the same night?

a) 8600°

b) 6840°

c) 6470°

d) 5930°

Question 5: Alarms from 3 different clocks sound after every 2, 4 and 6 hours, respectively. If the clocks are started at the same time, how many times do the alarms ring together in 3 days?

a) 6

b) 3

c) 9

d) 2

Question 6: If the number 1 on the clock is replaced by the letter ‘M’, the number 2 is replaced by ‘N’
and so on, then when thetime is 21:00 p.m. the hour hand will be at ………. letter.

a) T

b) S

c) V

d) U

Question 7: What is the angle between the two hands of a clock when the time shown by the clock is 8 p.m.?(in degrees)

a) 240

b) 120

c) 60

d) 50

Question 8: How many times in a week does both the hands of the clock will coincide with each other?

a) 84

b) 160

c) 56

d) 154

Question 9: Praneet started his journey at 2:45:46 p.m. and reached the destination at 4:55:57 p.m. Anit started the journey 58 mins 40secs after Praneet and reached his destination 50 mins 29 secs after him. How long did Anit take to complete his journey?

a) 2 hours 2 seconds

b) 2 hours 2 minutes

c) 1 hour 59 minutes

d) 2 hours 1 minute 12 seconds

Question 10: If the hour hand of a clock moves by $18^\circ$ then by how many degrees does the minute hand move during the same time?

a) 168

b) 216

c) 276

d) 196

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Question 11: What is the measure of the smaller of the two angles formed between the hour hand and the minute hand of a clock when it is 5:49 p.m.?

a) $119^\circ$

b) $119.5^\circ$

c) $120^\circ$

d) $120.5^\circ$

Question 12: What will be the acute angle between the hour-hand and the minute-hand at 2:13 p.m?

a) $16.5^\circ$

b) $18^\circ$

c) $13.5^\circ$

d) $12^\circ$

Question 13: In a week, how many times are the hands of clock at right angles with each other?

a) 308

b) 44

c) 24

d) 154

Question 14: What would be the smaller of the two angles formed by the hour hand and the minute hand at 3:47 p.m.?

a) $168.5^{0}$

b) $162^{0}$

c) $166.5^{0}$

d) $165^{0}$

Question 15: What is the measure of the smaller of the two angles formed between the hour hand and
the minute hand of a clock when it is 6:44 p.m.?

a) $ 62.5^\circ$

b) $ 62^\circ $

c) $ 84^\circ $

d) $ 83.5^\circ $

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Question 16: What will be the measure of the acute angle formed between the hour hand and the minute hand at 6:43 a.m.?

a) $ 21.5^\circ $

b) $ 78^\circ $

c) $ 56^\circ $

d) $ 56.5^\circ $

Question 17: What would be the smaller of the two angles formed by the hour hand and the minute hand at 4 : 52 p.m.?

a) $ 162^\circ $

b) $ 164.5^\circ $

c) $ 165^\circ $

d) $ 166^\circ $

Question 18: A watch loses 5 minutes every hour and was set right at 6 a.m. on a Monday. When will it
show the correct time again?

a) 6 a.m. on next Sunday

b) 3 a.m. on next Monday

c) 3 a.m. on next Sunday

d) 6 a.m. on next Monday

Question 19: What is the obtuse angle formed by the hands of a clock when the time in the clock is 2:30?

a) $95^\circ$

b) $120^\circ$

c) $105^\circ$

d) $165^\circ$

Question 20: A clock is found to be slow by 5 minutes at 8 AM on Sunday. It started gaining time and was found to be 5 minutes fast at 8 PM on Monday. When was it correct?

a) 8 AM, Monday

b) 2 AM, Monday

c) 6 AM, Monday

d) 8 PM, Monday

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Answers & Solutions:

1) Answer (C)

In every hour , hour hand covers $30^\circ$.

So, at 10:25 pm , angle covered by hour hand will be ,

$ \frac{30 \times 125 }{12} = 312.5^\circ$

In every hour , minute hand will cover $360^\circ$

So, at 10:25 pm , angle covered by minute hand will be ,

$60 \times 25  = 150^\circ$

angle between the hour hand and the minute hand of a clock = $312.5^\circ – 150^\circ$ = $162\frac{1}{2}°$

So, the answer would be option c)$162\frac{1}{2}°$

2) Answer (B)

LCM of 15, 20, 30 = 60

After each 60 minutes they will ring together.

Hence they next ring together at 12 noon .

3) Answer (B)

We will take the LCM of 20, 24, 30, which is 120.

It tells us that they will together after an interval of 120 seconds = 2 minutes.

So, at 11:27 a.m they will next ring together.

4) Answer (B)

5) Answer (A)

If we take the LCM of 2, 4 and 6 hours then got 12 hours.

In 12 hours alarms ring simultaneously once.

It means 12 hours = 1.

Hence 3 days = 72 hours = 6.

6) Answer (D)

7) Answer (B)

The total angle in a clock is 360°.

The minute hand covers this 360° in 60 minutes. Thus ,for every minute it covers 6°.

The hour hand covers this 360° in 12 hour. Thus ,for every hour it covers 30°.

So, in 8 hour ,the hour hand will cover $8\times30°=240°.$

So, the difference between hour hand and minute hand at 8 p.m will be = $\left(360°-240°\right)=120°.$

So, option B is correct .

8) Answer (D)

AM : 12:00, 1:05, 2:11, 3:16,4:22, 5:27, 6:33, 7:38, 8:44, 9:49, 10:55.

PM: 12:00, 1:05, 2:11, 3:16, 4:22, 5:27, 6:33, 7:38, 8:44, 9:49, 10:55.

So, both the hands coincide with each other for 22 times in a day.

Now,

For 1 day = 22 times.

For 1 week = 22 * 7

= > 154 times.

9) Answer (B)

Praneet started his journey at 2:45:46 pm

Anit started 58 minutes 40 secs later

so the time would be 2:45:46 + 0:58:40 = 3:44:26 pm (since 60 sec is 1 minute and 60 minute = 1 hour)

Praneet reaches at 4:55:57 pm

and Anit reaches 0:50:29 after him

so the reaching time would be 4:55:57+0:50:29 = 5:46:26 pm

now the time taken by Anit is 5:46:26 – 3:44:26 = 2:02:00

Hence the time taken by Anit is 2 hours and 2 mins

10) Answer (B)

The hour hand of a clock moves by 30 deg when the minute had moved through 360 deg. Hence if the hour hand moves 18 deg, then the minute hand moves by $\frac{360\times18}{30}$ = 216 deg

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11) Answer (B)

The hour hand moves 360 degrees every 12 hours. At 5:49, its angle is $(5 + \frac{49}{60}) \times\frac{ 360}{12} = 174.5 degrees$

The minute hand moves 360 degrees each 60 minutes, so at 15 minutes past the hour it has moved $\frac{49}{60} \times 360 = 294 degrees.$

Thus, the difference between the two hands is 294 – 174.5 = 119.5 degrees.

12) Answer (D)

angle covered by minute hand in 1 minute is 6degree and angle covered by hour hand in 1minute is $\frac {1}{2}$ degree.

So, angle covered by minute hand at 13minutes = $13\times 6degree$ = 78degree.

Hence, at 2hours 13minutes  = 133 x $\frac {1}{2}$degree = 66degree.

Hence, the angle between the hour and minute hand at 2.13PM = 78degree – 66degree = $12^\circ$

13) Answer (A)

If you switch to a rotating coordinate system in which the hour hand stands still, then the minute hand makes only 11 revolutions, and so it is at right angles with the hour hand 22 times. In a 24 hour day you get $2\times 22= 44$

so in weekthere are 7 days

so,

$7\times 44= 308 times$

14) Answer (A)

The minute hand moves 6 degrees per minute. (That’s 360 degrees divided by 60 minutes)

The hour hand moves one-twelfth that, or $\frac{1}{2}$ degree per minute.

So the angle between the minute and hour hand increases by 5.5 degrees every minute.

The minute and hour hand start together at noon.

It takes 227 minutes(60+60+60+47) to get to 3:47 . So in this time, the angle between the hour and minute hand has increased $227\times 5.5$ degrees.

$227\times 5.5$= 1248.5 degrees.

Which is the same as 168.5 degrees.(1 cicrle is 360 so in 1248.5 deg  there are 3 circle and 168.5 deg left)

15) Answer (B)

A clock is a circle, and a circle always contains 360 degrees. Since there are 60 minutes on a clock, each minute mark is 6 degrees.

$\frac{360^\circ total}{60 minutes total}=6^\circ per  minute$

The minute hand on the clock will point at 44 minutes, allowing us to calculate it’s position on the circle.

(44 min)(6)=$264^\circ$

Since there are 12 hours on the clock, each hour mark is 30 degrees.

$\frac{360^\circ total}{12 hours total}=30^\circ per  hour$

We can calculate where the hour hand will be at 6:00.

$(6 hr)(30)=180^\circ$

However, the hour hand will actually be between the 6 and 7, since we are looking at 6:44 rather than an absolute hour mark. 44 minutes is equal to $\frac{44}{60}$th of an hour. Use the same equation to find the additional position of the hour hand.

$180^\circ + \frac{44}{60} \times 30 = 202^\circ$

We are looking for the smaller angle between the two hands of the clock. The will be equal to the difference between the two angle measures.

Required answer = $264^\circ – 202^\circ = 62^\circ$

So, the answer would be option b)$ 62^\circ $.

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16) Answer (D)

A clock is a circle, and a circle always contains 360 degrees. Since there are 60 minutes on a clock, each minute mark is 6 degrees.

$\frac{360^\circ total}{60 minutes total}=6^\circ per minute$

The minute hand on the clock will point at 43 minutes, allowing us to calculate it’s position on the circle.

(43 min)(6)=$258^\circ$

Since there are 12 hours on the clock, each hour mark is 30 degrees.

$\frac{360^\circ total}{12 hours total}=30^\circ per hour$

We can calculate where the hour hand will be at 6:00.

$(6 hr)(30)=180^\circ$

However, the hour hand will actually be between the 6 and 7, since we are looking at 6:43 rather than an absolute hour mark. 43 minutes is equal to $\frac{43}{60}$th of an hour. Use the same equation to find the additional position of the hour hand.

$180^\circ + \frac{43}{60} \times 30 = 201.5^\circ$

We are looking for the acute angle between the two hands of the clock. The will be equal to the difference between the two angle measures.

Required answer = $258^\circ – 201.5^\circ = 56.5^\circ$

So, the answer would be option b)$ 56.5^\circ $.

17) Answer (D)

18) Answer (A)

For the watch to show the correct time again, it should lose 12 hours.
It loses 5 minutes in 1 hour.
⇒ It loses 1 minute in 12 minutes.
⇒ It will lose 12 hours (or 720 minutes) in 720 × 12 minutes = 8640 minutes = 144 hours = 6 days.
⇒Thus, the clock will show the correct time again at 6am on next Sunday.

So , the answer would be option a) 6 a.m. on next Sunday.

19) Answer (C)

Angle between the hands of a clock is given by the formula $\dfrac{11}{2}H – 30M$ or $30M – \dfrac{11}{2}H$ where H is hours and M is minutes.
Here, Given time = 02 : 30, H = 2 and M = 30.
Angle = $\dfrac{11}{2} \times 30 – 30 \times 2 = 165 – 60 – 105^\circ$

20) Answer (B)

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