BITSAT Online Test Papers

Question

Q.1 There is 1m long aerial in car, moving from south to north with the speed of 100 km/hr. If the horizontal component of earthâ€™s magnetic field is 0.18 oersted, the emf induced in the aerial is

Possible Answers

Selected	Possible Answer
	0.5 mV
	1 mV
	0.25 V
	0 V

Question

Q.2 A potential difference develops across the conducting rod AB, when it is moved between the pole pieces of a magnet in the direction

Possible Answers

Selected	Possible Answer
	R
	Q
	S
	P

Question

Q.3 A magnet is approaching towards a stationary circular loop along its axis with the velocity v and an emf e is induced in the loop. If the loop also starts velocity v, towards magnet the emf induced in the loop will now be

Possible Answers

Selected	Possible Answer
	2e
	e/2
	e
	4e

Question

Choose .the wrong statement.

Possible Answers

Selected	Possible Answer
	An emf may be induced in a conductor by moving it in a uniform magnetic field
	Inserting an iron core in a coil increases itâ€™s self inductance
	The self-induced emf in a coil due to a changing current in it always tends to decrease the current
	The direction of induced current is such as to oppose the change in magnetic flux that causes it

Question

Q.5 A conducting rod of length rotates with a uniform angular velocity $\omega$ about an axis passing through its centre O and perpendicular to itself in a uniform magnetic field $\overset{\omega}{B}$ , acting parallel to the axis of rotation. The emf induced between the ends of rod will be

Possible Answers

Selected	Possible Answer
	zero
	$\frac{1}{8} \omega B1^2$
	$\frac{1}{4} \omega B1^2$
	$\frac{1}{2} \omega B1^2$

Question

Q.6 A dynamo dissipates 20 W, when it supplies a current of 4A through it. If itâ€™s terminal potential difference is 220V, then the emf induced in it is

Possible Answers

Selected	Possible Answer
	230 V
	215 V
	220 V
	225 V

Question

Q.7 As the speed of an electric fan increases, the current through it

Possible Answers

Selected	Possible Answer
	increases
	decreases
	remains constant
	becomes maximum at the maximum speed

Question

Q.8 A small square loop of wire of side is placed inside a large square loop of side L(>>1). The loops are coplanar and their centres coincide. What is the mutual inductance of the system ?

Possible Answers

Selected	Possible Answer
	$\frac{\sqrt{2}\mu_0 1^2}{\pi L}$
	$\frac{2 \sqrt{2}\mu_0 L^2}{\pi 1}$
	$\frac{2\mu_0 1^2}{\pi L}$
	$\frac{2 \sqrt{2}\mu_0 1^2}{\pi L}$

Question

Q.9 An emf of 15 V is applied in a circuit, containing an inductance of 5 H and a resistance of $10 \Omega$ in series. The ratio of the current times $t = \infty$ and t = 1s is

Possible Answers

Selected	Possible Answer
	$\frac{1}{e}$
	$1- \frac{1}{e}$
	$\frac{\sqrt{e}}{\sqrt{e-1}}$
	$\frac{e^2}{e^2-1}$

Question

Q.10 An emf of 15 V is applied in a circuit, containing an inductance of 5 H and a resistance of $10 \Omega$ in series, the initial growth rate of current in the circuit is

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