QBManager

PHXI06:WORK ENERGY AND POWER

355787 Assertion :
Work done in uniform circular motion is zero.
Reason :
Force is always directed along displacement.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

PHXI06:WORK ENERGY AND POWER

355788 The statements which show negative work are $A$ . Work done by force of viscosity which increases with increase in velocity. $B$ . Work done by attractive forces when particles are taken away from each other. $C$ . Work done when applied force decreases kinetic energy of the body. $D$ . Work done by gravity when a porter drops a suitcase from his head.

1

A, B, C

2

A, B, D

3

B, C, D

4

A, B, C, D

PHXI06:WORK ENERGY AND POWER

355789 The work done against gravity in taking 10 $k g$ mass at 1 $m$ height in1 sec will be

1 98

J

2

49 J

3

196 J

4 None of these

Explanation:

Work done $= m g h = 10 \times 9 \cdot 8 \times 1 = 98 J$ .

PHXI06:WORK ENERGY AND POWER

355790 A particle (mass $m$ ) is projected with an initial velocity $v$ at an angle $θ$ to the horizontal. What is the work done by the force of gravity from the instant of throwing to the instant it reaches the highest point?

1

- \frac{m v^{2} \sin^{2} θ}{2}

2 Zero

3

m v^{2} \sin^{2} θ

4

- m v^{2} \sin^{2} θ

Explanation:

$W_{m g} = K_{f} - K_{i} = \frac{1}{2} m (v \cos θ)^{2} - \frac{1}{2} m v^{2}$ $= \frac{1}{2} m v^{2} [\cos^{2} θ - 1] = - \frac{1}{2} m v^{2} \sin^{2} θ$

PHXI06:WORK ENERGY AND POWER

355787 Assertion :
Work done in uniform circular motion is zero.
Reason :
Force is always directed along displacement.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

PHXI06:WORK ENERGY AND POWER

355788 The statements which show negative work are $A$ . Work done by force of viscosity which increases with increase in velocity. $B$ . Work done by attractive forces when particles are taken away from each other. $C$ . Work done when applied force decreases kinetic energy of the body. $D$ . Work done by gravity when a porter drops a suitcase from his head.

1

A, B, C

2

A, B, D

3

B, C, D

4

A, B, C, D

PHXI06:WORK ENERGY AND POWER

355789 The work done against gravity in taking 10 $k g$ mass at 1 $m$ height in1 sec will be

1 98

J

2

49 J

3

196 J

4 None of these

Explanation:

Work done $= m g h = 10 \times 9 \cdot 8 \times 1 = 98 J$ .

PHXI06:WORK ENERGY AND POWER

355790 A particle (mass $m$ ) is projected with an initial velocity $v$ at an angle $θ$ to the horizontal. What is the work done by the force of gravity from the instant of throwing to the instant it reaches the highest point?

1

- \frac{m v^{2} \sin^{2} θ}{2}

2 Zero

3

m v^{2} \sin^{2} θ

4

- m v^{2} \sin^{2} θ

Explanation:

$W_{m g} = K_{f} - K_{i} = \frac{1}{2} m (v \cos θ)^{2} - \frac{1}{2} m v^{2}$ $= \frac{1}{2} m v^{2} [\cos^{2} θ - 1] = - \frac{1}{2} m v^{2} \sin^{2} θ$

PHXI06:WORK ENERGY AND POWER

355787 Assertion :
Work done in uniform circular motion is zero.
Reason :
Force is always directed along displacement.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

PHXI06:WORK ENERGY AND POWER

355788 The statements which show negative work are $A$ . Work done by force of viscosity which increases with increase in velocity. $B$ . Work done by attractive forces when particles are taken away from each other. $C$ . Work done when applied force decreases kinetic energy of the body. $D$ . Work done by gravity when a porter drops a suitcase from his head.

1

A, B, C

2

A, B, D

3

B, C, D

4

A, B, C, D

PHXI06:WORK ENERGY AND POWER

355789 The work done against gravity in taking 10 $k g$ mass at 1 $m$ height in1 sec will be

1 98

J

2

49 J

3

196 J

4 None of these

Explanation:

Work done $= m g h = 10 \times 9 \cdot 8 \times 1 = 98 J$ .

PHXI06:WORK ENERGY AND POWER

355790 A particle (mass $m$ ) is projected with an initial velocity $v$ at an angle $θ$ to the horizontal. What is the work done by the force of gravity from the instant of throwing to the instant it reaches the highest point?

1

- \frac{m v^{2} \sin^{2} θ}{2}

2 Zero

3

m v^{2} \sin^{2} θ

4

- m v^{2} \sin^{2} θ

Explanation:

$W_{m g} = K_{f} - K_{i} = \frac{1}{2} m (v \cos θ)^{2} - \frac{1}{2} m v^{2}$ $= \frac{1}{2} m v^{2} [\cos^{2} θ - 1] = - \frac{1}{2} m v^{2} \sin^{2} θ$

PHXI06:WORK ENERGY AND POWER

355787 Assertion :
Work done in uniform circular motion is zero.
Reason :
Force is always directed along displacement.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but reason is correct.

PHXI06:WORK ENERGY AND POWER

355788 The statements which show negative work are $A$ . Work done by force of viscosity which increases with increase in velocity. $B$ . Work done by attractive forces when particles are taken away from each other. $C$ . Work done when applied force decreases kinetic energy of the body. $D$ . Work done by gravity when a porter drops a suitcase from his head.

1

A, B, C

2

A, B, D

3

B, C, D

4

A, B, C, D

PHXI06:WORK ENERGY AND POWER

355789 The work done against gravity in taking 10 $k g$ mass at 1 $m$ height in1 sec will be

1 98

J

2

49 J

3

196 J

4 None of these

Explanation:

Work done $= m g h = 10 \times 9 \cdot 8 \times 1 = 98 J$ .

PHXI06:WORK ENERGY AND POWER

355790 A particle (mass $m$ ) is projected with an initial velocity $v$ at an angle $θ$ to the horizontal. What is the work done by the force of gravity from the instant of throwing to the instant it reaches the highest point?

1

- \frac{m v^{2} \sin^{2} θ}{2}

2 Zero

3

m v^{2} \sin^{2} θ

4

- m v^{2} \sin^{2} θ

Explanation:

$W_{m g} = K_{f} - K_{i} = \frac{1}{2} m (v \cos θ)^{2} - \frac{1}{2} m v^{2}$ $= \frac{1}{2} m v^{2} [\cos^{2} θ - 1] = - \frac{1}{2} m v^{2} \sin^{2} θ$

Question Bank Series

Explanation:

Explanation:

Explanation:

Explanation:

Explanation:

Explanation:

Explanation:

Explanation:

Explanation:

Explanation:

Explanation:

Explanation:

Question Bank Series

Explanation:

Explanation:

Explanation:

Explanation: