# Physics (NTSE Stage-2 (National-Level) Scholastic-Aptitude & Language Comprehension): Questions 68 - 71 of 73

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## Question number: 68

» Physics » Motion and Force

MCQ▾

### Question

An electron moving with uniform velocity in x direction enters a region of uniform magnetic field along y direction. Which of the following physical quantity (ies) is (are) non-zero and remain constant?

I. Velocity of the electron.

II. Magnitude of the momentum of the electron.

III. Force on the electron.

IV. The kinetic energy of electron.

### Choices

Choice (4) Response

a.

Only II and IV

b.

All four

c.

Only I and II

d.

Only III and IV

## Question number: 69

» Physics » Motion and Force

MCQ▾

This graph shows

### Choices

Choice (4) Response

a.

Constant acceleration

b.

Constant velocity

c.

Constant speed

d.

All of the above

## Question number: 70

» Physics » Motion and Force

MCQ▾

### Question

Consider the following statements

I. Grease is used to reduce friction in bicycle chain.

II. Ball bearings are used to reduce friction in a fan.

III. Oil can be used to increase friction in a car engine.

IV. Talc can be used to reduce friction when an object is sliding on a surface.

Which of the above statement (s) is/are correct?

### Choices

Choice (4) Response

a.

I, II, and III

b.

I, III, and IV

c.

I, II, and IV

d.

II, III, and IV

## Question number: 71

» Physics » Light

MCQ▾

### Question

Two mirrors are placed at right angles to each other as shown in the figure. Total number of images of an object ‘o’ placed between them, which are seen as

### Choices

Choice (4) Response

a.

Six

b.

Four

c.

Three

d.

Two

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