The magnitude of torque on dipole is maximum if

(a)

θ = 0^o

(b)

θ = 90^o

(c)

θ = 180^o

(d)

θ = 270^o

The expression for water equivalent is _____________.

(a)

W = H (θ₂,θ₁)

(b)

W = \(\frac { { \theta }_{ 2 }-{ \theta }_{ 1 } }{ H } \)

(c)

both (a) and (b)

(d)

W = \(\frac { H }{ { \theta }_{ 2 }-{ \theta }_{ 1 } } \)

For an ideal transformer __________

(a)

E_pI_p = E_sI_s

(b)

E_pE_s = I_p

(c)

E_pE_s = I_s

(d)

I_pI_s = E_sI_s

Accelerated charges would produce _____________.

(a)

sound waves

(b)

૪-rays

(c)

magnetic waves

(d)

electromagnetic waves

_________ spectra are used for making dyes

(a)

continuous emission

(b)

band emission

(c)

band absorption

(d)

line spectra

It is desired to photograph the image of an object placed at a distance of 3m from the plane mirror. The camera which is at a distance of 4.5 m from the mirror should be focused for a distance of ___________.

(a)

3 m

(b)

4.5 m

(c)

6 m

(d)

7.5 m

A small piece of wire bent into an L shape with an upright and horizontal portion of equal length, is placed with the horizontal portion along the axis of the concave mirror whose radius of curvature is 10 cm. If the bend is 20 cm from the pole of the mirror, then the ratio of lengths of the image of the upright and horizontal position of the wire is _____________.

(a)

1: 2

(b)

3: 1

(c)

1: 3

(d)

2: 1

Which phenomenon supports that matter has a wave nature?

(a)

electron momentum

(b)

electron diffraction

(c)

photon momentum

(d)

photon diffraction

The fig. represents the observed intensity of X-rays emitted by an X-ray tube as a function of wavelength. The sharp peaks A and B denote ____________.
 

(a)

continuous spectrum

(b)

band spectrum

(c)

characteristic spectrum

(d)

white radiations

In an N-P-N transistor circuit, the emitter, collector, and base current are respectively I_E, I_C, and l_B. The relation between them is _____________.

(a)

I_C EB

(b)

I_B CE

(c)

I_B > I_C > I_E

(d)

I_B > I_C > I_E