# Work, Energy and Power-Work Done (KVPY Stream SB-SX (Class 12 & 1st Year B.Sc.) Physics): Questions 1 - 3 of 4

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## Question number: 1

» Work, Energy and Power » Work Done

Appeared in Year: 2012

MCQ▾

### Question

A conducting rod of mass m and length l is free to move without friction on two parallel long conducting rails, as shown below. There is a resistance R across the rails. In the entire space around, there is a uniform magnetic field B normal to the plane of the rod and rails. The rod is given an impulsive velocity v0.

Finally, the initial energy

### Choices

Choice (4) Response

a.

will be converted fully into magnetic energy due to induced current

b.

will enable rod to continue to move with velocity v0 since the rails are frictionless

c.

will be converted fully into heat energy in the resistor

d.

will be converted into the work done against the magnetic field

## Question number: 2

» Work, Energy and Power » Work Done

MCQ▾

### Question

A block of mass 15 kg slides down a rough slope which is inclined at 600 to the horizontal. The coefficient of sliding friction is 0.25. When the block has slid 10 m, the work done on the block by the force of friction is nearly,

### Choices

Choice (4) Response

a.

b.

c.

d.

115.75 J

## Question number: 3

» Work, Energy and Power » Work Done

MCQ▾

### Question

A particle of mass 1 kg has potential energy, . At, the particle is at rest (5, 3). Work done by external force to displace the particle from rest to the point of crossing the x axis is –

### Choices

Choice (4) Response

a.

13 J

b.

c.

d.

169 J

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