2
Q:

# A man stands in a lift which accelerates upwards. The resultant reaction force on the floor of the lift is

 A) greater than the weight of the man B) less than the weight of the man C) Same as the weight of the man D) Zero

Answer:   A) greater than the weight of the man

Explanation:

The weight of the man mg is acting on the floor. As the lift is moving up with an acceleration, say a, the man too in it is having this acceleration. The force producing this acceleration is ma. By Newton's third law, this force will have an equal reaction pressing the floor equal to ma. Therefore the total resultant reaction on the floor is mg+ma = m(g+a) which is mg, the weight of the man. So (a) is correct.

Subject: Physics
Q:

If the velocity of a body is doubled its momentum ________________.

 A) remains same B) doubles C) becomes half D) becomes 4 times

Explanation:

Filed Under: Physics
Exam Prep: AIEEE , Bank Exams

2 3105
Q:

A body of mass 8 kg is moving with a velocity of 4 m/s, find its momentum.

 A) 2 B) 64 C) 32 D) 4

Explanation:

Filed Under: Physics
Exam Prep: AIEEE , Bank Exams

0 3298
Q:

Ozone at the higher level of the atmosphere is a product of ______ acting on oxygen molecules.

Explanation:

Filed Under: Physics
Exam Prep: Bank Exams

1 5321
Q:

'Torr' is a unit of _______.

 A) force B) energy C) power D) pressure

Explanation:

Filed Under: Physics
Exam Prep: Bank Exams

6 4144
Q:

What is the velocity of sound in air?

 A) 343 m/sec B) 110 m/sec C) 220 m/sec D) 232 m/sec

Explanation:

Filed Under: Physics
Exam Prep: AIEEE , Bank Exams

4 3811
Q:

The power of a lens is —2.5 D. The type of lens and its focal length are respectively:

 A) Convex, -0.40 m B) Concave, -0.40 m C) Concave, 0.40 m D) Convex, 0.40 m

Explanation:

Filed Under: Physics
Exam Prep: Bank Exams

0 3907
Q:

Which one of the following is the unit of force?

 A) Pascal B) Watt C) Joule D) Newton

Explanation:

Filed Under: Physics
Exam Prep: Bank Exams

0 3351
Q:

Which of the following are Mechanical waves?

 A) X rays B) Radio waves C) Microwaves D) Sound waves