Physics Test 118

Question 1
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In the given figure if i₁ = 3 sin ωt and i₂ = 4 cos ωt, then i₃ is

A
5 sin (ωt + 53°)

B
5 sin (ωt + 37°)

C
5 sin (ωt + 45°)

D
5 cos (ωt + 53°)

Question 2
4 / -1

For the given ac circuit source voltage is given by V = 100 sin (10t +π/2 ) where V is in volt and t is in second.

A
Power factor of the given circuit is 1/2.

B
Current as a function of time t is given by i(A) = 5 sin (10t + π/2)

C
Voltage across resistor as a function of time 't' is given by v = 50√3 sin (10t + π/2 )

D
Voltage across inductor as a function of time 't' is given by v = 50 sin (10t + 5π/6)

Question 3
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A constant force F is applied on the rod of mass M and length L placed between two conducting fixed rails in a uniform magnetic field. A capacitor C is connected between the two rails as shown in the diagram. Neglecting the resistance of the rod and the rails, which of the following statement is incorrect.

A
Acceleration of rod is constant.

B
Current in the wire is constant and nonzero.

C
Charge on the capacitor is constant.

D
Magnetic force on the rod is towards left.

Question 4
4 / -1

The moment of inertia about x-axis of uniform thin plate of density ρ kg/m² as shown in the figure is , then find the value of N.

A
1

B
2

C
4

D
5

Question 5
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A block and a cylinder (with I = βmR²), both of mass m, lie on a plane (inclined at an angle θ), touching each other as shown in figure. There is sufficient friction between the cylinder and the plane so that it rolls without slipping. But the bottom of the block is coated with grease, so there is no friction between it and the plane. However, there is a coefficient of kinetic friction µ = 1 between the block’s right face and the cylinder. Assume that θ is small enough so that the block’s bottom face remains in contact with the plane at all times

What is the acceleration of block?

A
g sin θ

B

C

D

Question 6
4 / -1

A block and a cylinder (with I = βmR²), both of mass m, lie on a plane (inclined at an angle θ), touching each other as shown in figure. There is sufficient friction between the cylinder and the plane so that it rolls without slipping. But the bottom of the block is coated with grease, so there is no friction between it and the plane. However, there is a coefficient of kinetic friction µ = 1 between the block’s right face and the cylinder. Assume that θ is small enough so that the block’s bottom face remains in contact with the plane at all times

What is the condition for θ for which the block's bottom face remains in contact with the plane at all times?

A

B

C

D

Question 7
4 / -1

The circuit consists of a capacitor connected in parallel to a resistor R with a coil of inductance L in series with them. The power source could be an AC or a constant voltage DC source. When AC source is applied then X_L = X_C = R.

If an AC source is applied across the input terminal, then

A
The peak value of current through AC source will be .

B
The peak value of current through AC source will be .

C
The peak current across capacitor will be .

D
option 1 and option 3 are correct

Question 8
4 / -1

The circuit consists of a capacitor connected in parallel to a resistor R with a coil of inductance L in series with them. The power source could be an AC or a constant voltage DC source. When AC source is applied then X_L = X_C = R.

If a constant DC source of voltage 𝛏₀ is applied across the input terminal with a switch, then :-

A
Just after the switch is closed the initial current through the voltage source will be zero.

B
The current through the voltage source long time after the switch is closed will be zero.

C
The current through the voltage source long time after the switch is closed will be .

D
option 1 and option 3 are correct

Question 9

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A solid sphere of radius R = 0.5m is placed on a rough surface. A force F = 7 N is applied at point A. Sphere starts to perform pure rolling. Height of point A varies as h = h₀ + kt where h₀ = 0.1m, k = 0.4 m/sec

	List-I		List-II
(P)	At t = 5/4 sec frictional force acting on sphere will be	(1)	backward
(Q)	At t = 3/2 sec frictional force acting on sphere will be	(2)	forward
(R)	At t = 7/4 sec frictional force acting on sphere will be	(3)	0
(S)	Work done by friction force from t = 0 to t = 7/4 sec	(4)	1N
		(5)	the magnitude of frictional force is independent of applied force

P → 1,4,Q → 3,5,R → 2,4,S → 3

P → 1,3,Q → 3,5,R → 2,4,S → 4

P → 1,5,Q → 3,5,R → 2,4,S → 3

P → 1,2,Q → 3,5,R → 2,4,S → 3

Question 10

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Answer the following by appropriately matching the lists based on the information given in the paragraph.

A uniform rod of length L is suspended from its end by a smooth hinge. The rod is free to rotate in a vertical plane. If the rod is given an angular velocity of at the lowest point.

	List-I		List-II
(I)	Force exerted by the hinge in the horizontal direction	(P)	increases continuously till the rod stops
(II)	Force exerted by the hinge in the vertical direction	(Q)	decreases continuously till the rod stops
(III)	Magnitude of Angular velocity of the rod	(R)	increases and then decreases till the rod stops
(IV)	Magnitude of Angular acceleration of the rod	(S)	decreases and then increases till the rod stops
		(T)	decreases and increases in a periodic manner
		(U)	increases and decreases in a periodic manner